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O’Brien TJ, Goosey-Tolfrey VL, Leicht CA. Compromised heat loss leads to a delayed ice slurry induced reduction in heat storage. PLoS One 2024; 19:e0305068. [PMID: 39121053 PMCID: PMC11315292 DOI: 10.1371/journal.pone.0305068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 05/22/2024] [Indexed: 08/11/2024] Open
Abstract
Compromised heat loss due to limited convection and evaporation can increase thermal strain. We aimed to determine the effectiveness of ice slurry ingestion to reduce thermal strain following hyperthermia in a state of compromised heat loss. Twelve healthy males (age: 25 ± 4y) underwent hot water immersion to elevate rectal temperature (Trec) by 1.82 ± 0.08°C on four occasions. In the subsequent 60-min of seated recovery, participants ingested either 6.8 g·kg-1 of ice slurry (-0.6°C) or control drink (37°C) in ambient conditions (21 ± 1°C, 39 ± 10% relative humidity), wearing either t-shirt and shorts (2 trials: ICE and CON) or a whole-body sweat suit (2 trials: ICE-SS and CON-SS). Trec and mean skin temperature (Tsk) were recorded and a two-compartment thermometry model of heat storage was calculated. Heat storage was lower in ICE compared with CON at 20-40min (p ≤ 0.044, d ≥ 0.88) and for ICE-SS compared with CON-SS at 40-60 min (p ≤ 0.012, d ≥ 0.93). Trec was lower in ICE compared with CON from 30-60min (p ≤ 0.034, d ≥ 0.65), with a trend for a reduced Trec in ICE-SS compared with CON-SS at 40min (p = 0.079, d = 0.60). A greater Tsk was found in ICE-SS and CON-SS compared with ICE and CON (p < 0.001, d ≥ 3.37). A trend for a lower Tsk for ICE compared with CON was found at 20-40min (p ≤ 0.099, d ≥ 0.53), no differences were found for ICE-SS vs CON-SS (p ≥ 0.554, d ≤ 0.43). Ice slurry ingestion can effectively reduce heat storage when heat loss through convection and evaporation is compromised, relevant to those wearing personal protective equipment or those with compromised sweat loss. Compromised heat loss delays the reduction in heat storage, possibly related to ice slurry ingestion not lowering Tsk.
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Affiliation(s)
- Thomas J. O’Brien
- Peter Harrison Centre for Disability Sport; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Victoria L. Goosey-Tolfrey
- Peter Harrison Centre for Disability Sport; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Christof A. Leicht
- Peter Harrison Centre for Disability Sport; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
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Kenny GP, Tetzlaff EJ, Journeay WS, Henderson SB, O’Connor FK. Indoor overheating: A review of vulnerabilities, causes, and strategies to prevent adverse human health outcomes during extreme heat events. Temperature (Austin) 2024; 11:203-246. [PMID: 39193048 PMCID: PMC11346563 DOI: 10.1080/23328940.2024.2361223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 05/07/2024] [Accepted: 05/20/2024] [Indexed: 08/29/2024] Open
Abstract
The likelihood of exposure to overheated indoor environments is increasing as climate change is exacerbating the frequency and severity of hot weather and extreme heat events (EHE). Consequently, vulnerable populations will face serious health risks from indoor overheating. While the relationship between EHE and human health has been assessed in relation to outdoor temperature, indoor temperature patterns can vary markedly from those measured outside. This is because the built environment and building characteristics can act as an important modifier of indoor temperatures. In this narrative review, we examine the physiological and behavioral determinants that influence a person's susceptibility to indoor overheating. Further, we explore how the built environment, neighborhood-level factors, and building characteristics can impact exposure to excess heat and we overview how strategies to mitigate building overheating can help reduce heat-related mortality in heat-vulnerable occupants. Finally, we discuss the effectiveness of commonly recommended personal cooling strategies that aim to mitigate dangerous increases in physiological strain during exposure to high indoor temperatures during hot weather or an EHE. As global temperatures continue to rise, the need for a research agenda specifically directed at reducing the likelihood and impact of indoor overheating on human health is paramount. This includes conducting EHE simulation studies to support the development of consensus-based heat mitigation solutions and public health messaging that provides equitable protection to heat-vulnerable people exposed to high indoor temperatures.
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Affiliation(s)
- Glen P. Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Emily J. Tetzlaff
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada
| | - W. Shane Journeay
- Departments of Medicine and Community Health and Epidemiology, Dalhousie Medicine New Brunswick and Dalhousie University, Saint John, NB, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, University of Toronto, Toronto, ON, Canada
- Department of Rehabilitative Care, Providence Healthcare-Unity Health Toronto, Toronto, ON, Canada
| | - Sarah B. Henderson
- Environmental Health Services, British Columbia Centre for Disease Control, Vancouver, BC, Canada
- National Collaborating Centre for Environmental Health, Vancouver, BC, Canada
| | - Fergus K. O’Connor
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada
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3
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Andrade MT, Wanner SP, Santos WME, Mendes TT, Nunes-Leite MMS, de Oliveira GGA, Carmo AAL, Carvalho MV, Silami Garcia E, Soares DD. Ad libitum ice slurry ingestion and half-marathon performance in a hot environment: A study comparing the effects of the amount and moment of ingestion between ice slurry and water at 37 °C. J Therm Biol 2024; 119:103781. [PMID: 38232473 DOI: 10.1016/j.jtherbio.2023.103781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 12/07/2023] [Accepted: 12/21/2023] [Indexed: 01/19/2024]
Abstract
Ice slurry ingestion during prolonged exercises may improve performance in hot environments; however, the ideal amount and timing of ingestion are still uncertain. We determined whether ad libitum ice slurry ingestion influences physiological and perceptual variables and half-marathon performance while comparing the effects of the amount and moment of ingestion between ice slurry and water at 37 °C. Ten trained participants (28 ± 2 years; mean and SD) were required to run two half marathons while consuming either ice slurry (-1 °C; Ad-1) or water (37 °C; 37 CE) ad libitum. They then performed two other half marathons where, during one, they were required to ingest an amount of water equivalent to the amount consumed during the Ad-1 trial (Pro37), and in the other, to ingest ice slurry in the amount consumed during the 37 CE trial (Pro-1). During the half marathons, dry-bulb temperature and relative humidity were controlled at 33.1 ± 0.3 °C and 60 ± 3%, respectively. Ad-1 ingestion (349.6 ± 58.5 g) was 45% less than 37 CE ingestion (635.5 ± 135.8 g). Physical performance, heart rate, perceived exertion, body temperatures, and thermal perception were not influenced by the temperature or amount of beverage ingestion. However, a secondary analysis suggested that lower beverage ingestion was associated with improved performance (Ad-1 + Pro37 vs. 37 CE + Pro-1: -4.0 min, Cohen's d = 0.39), with a significant relationship between lower beverage ingestion and faster running time (b = 0.02, t = 4.01, p < 0.001). In conclusion, ice slurry ingestion does not affect performance or physiological or perceptual variables during a half marathon in a hot environment. Preliminary evidence suggests that lower beverage ingestion (ice slurry or warm water) is associated with improved performance compared to higher ingestion.
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Affiliation(s)
- Marcelo T Andrade
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil; Psychology Program, Belo Horizonte, (MG), Brazil.
| | - Samuel P Wanner
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil
| | - Weslley M E Santos
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil
| | - Thiago T Mendes
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil; Department of Physical Education, Universidade Federal da Bahia, Salvador, (BA), Brazil
| | - Matheus M S Nunes-Leite
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil
| | - Gustavo G A de Oliveira
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil
| | - Adriano A L Carmo
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil
| | - Moisés V Carvalho
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil; Department of Human Movement Sciences, Universidade Do Estado de Minas Gerais, Ibirité, (MG), Brazil
| | - Emerson Silami Garcia
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil
| | - Danusa D Soares
- Exercise Physiology Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, (MG), Brazil
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O'Brien TJ, Goosey-Tolfrey VL, Leicht CA. Rectal and gastrointestinal temperature differ during passive heating and subsequent recovery. J Therm Biol 2024; 119:103755. [PMID: 38242073 DOI: 10.1016/j.jtherbio.2023.103755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 11/02/2023] [Accepted: 11/06/2023] [Indexed: 01/21/2024]
Abstract
We aimed to compare rectal temperature (Trec) and gastro-intestinal temperature (TGI) during passive heating and subsequent recovery with and without ice slurry ingestion. Twelve males (age: 25 ± 4 years, body mass index: 25.7 ± 2.5 kg m-2) were immersed in hot water on two occasions (Trec elevation: 1.82 ± 0.08°C). In the subsequent 60-min recovery in ambient conditions, participants ingested either 6.8 g kg-1 of ice slurry (-0.6°C, ICE) or control drink (37°C, CON). During passive heating, Trec was lower than TGI (P < 0.001), in the recovery, Trec was higher than TGI (P < 0.001). During passive heating, mean bias and 95%LoA (Limits of Agreement) were -0.10(±0.25)°C and -0.12(±0.36)°C for CON and ICE, respectively. In the recovery, mean bias and 95%LoA were 0.30(±0.60)°C and 0.42(±0.63)°C for CON and ICE, respectively. Trec and TGI differed during both heating and recovery, and less favourable agreement between Trec and TGI was found in the recovery from passive heating with or without ice slurry ingestion.
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Affiliation(s)
- Thomas J O'Brien
- Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Victoria L Goosey-Tolfrey
- Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Christof A Leicht
- Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
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Choo HC, Choo DHW, Tan I, Chang J, Chow KM, Lee JKW, Burns SF, Ihsan M. Effect of ice slurry ingestion on thermoregulatory responses during fixed-intensity cycling in humid and dry heat. Eur J Appl Physiol 2023; 123:2225-2237. [PMID: 37256293 DOI: 10.1007/s00421-023-05235-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 05/21/2023] [Indexed: 06/01/2023]
Abstract
PURPOSE This study examined the thermoregulatory response and ergogenic effects of ice slurry (ICE) ingestion in hot environments with high and low relative humidity (RH). METHODS Eight males completed four trials in a crossover manner in dry (DRY: 34.7 ± 0.2 °C, 38 ± 2%RH) and humid heat (HUM: 34.8 °C ± 0.2 °C, 80 ± 1%RH). They ingested 8.0 g·kg-1 of ICE (0.0 °C) or 37.5 °C water (CON) during 30 min before exercise, and three aliquots (3.2 g·kg-1) of ICE or CON during 45-min cycling at 50%[Formula: see text]O2peak, followed by cycling to exhaustion at 80%[Formula: see text]O2peak (TTE). Body core temperature (Tcore), mean skin temperature (Tsk), heart rate (HR), thermal comfort, thermal sensation and rating of perceived exertion (RPE) were measured. RESULTS Relative to CON, ICE improved TTE by 76.5 ± 96.5% in HUM and 21.3 ± 44.9% in DRY (p = 0.044). End-exercise Tcore was lower in ICE versus CON in DRY (37.8 ± 0.4 °C versus 38.1 ± 0.3 °C, p = 0.005) and HUM (38.8 ± 0.4 °C versus 39.3 ± 0.6 °C, p = 0.004). ICE decreased HR, heat storage and heat strain index only in DRY (p < 0.001-0.018). ICE improved thermal sensation and comfort in DRY and HUM (p < 0.001-0.011), attenuated RPE in HUM (p = 0.012) but not in DRY (p = 0.065). CONCLUSION ICE tended to benefit performance in humid heat more than in dry heat. This is likely due to the reduced extent of hyperthermia in dry heat and the relative importance of sensory inputs in mediating exercise capacity.
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Affiliation(s)
- Hui Cheng Choo
- Sport Physiology Department, Sport Science and Medicine Centre, Singapore Sport Institute, 3 Stadium Drive, Singapore, 397630, Singapore.
| | - Darine Hui Wen Choo
- Sport Physiology Department, Sport Science and Medicine Centre, Singapore Sport Institute, 3 Stadium Drive, Singapore, 397630, Singapore
| | - Isabelle Tan
- Nanyang Technological University, National Institute of Education, 1 Nanyang Walk, Singapore, 637616, Singapore
| | - Jared Chang
- Faculty of Health and Behavioral Sciences, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
| | - Kin Ming Chow
- Sport Physiology Department, Sport Science and Medicine Centre, Singapore Sport Institute, 3 Stadium Drive, Singapore, 397630, Singapore
| | - Jason Kai Wei Lee
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, Singapore, 117593, Singapore
| | - Stephen Francis Burns
- Nanyang Technological University, National Institute of Education, 1 Nanyang Walk, Singapore, 637616, Singapore
| | - Mohammed Ihsan
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, Singapore, 117593, Singapore
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Alhadad SB, Chua MCY, Lee JKW, Low ICC. The effects of low and normal dose ice slurry ingestion on endurance capacity and intestinal epithelial injury in the heat. J Sci Med Sport 2023:S1440-2440(23)00078-6. [PMID: 37179242 DOI: 10.1016/j.jsams.2023.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 04/22/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023]
Abstract
OBJECTIVES Compare the effects of ice slurry ingestion at low and normal doses on endurance capacity and exertional heat stress-induced gastrointestinal perturbations. DESIGN Randomised, cross-over design. METHODS Twelve physically active males completed four treadmill running trials, ingesting ice slurry (ICE) or ambient drink (AMB) at 2 g·kg-1 (Normal; N) or 1 g·kg-1 (Low; L) doses every 15-min during exercise and 8 g·kg-1 (N) or 4 g·kg-1 (L) pre- and post-exercise. Pre-, during and post-exercise serum intestinal fatty-acid binding protein ([I-FABP]) and lipopolysaccharide ([LPS]) concentrations were determined. RESULTS Pre-exercise gastrointestinal temperature (Tgi) was lower in L + ICE than L + AMB (p < 0.05), N + ICE than N + AMB (p < 0.001) and N + ICE than L + ICE (p < 0.001). Higher rate of Tgi rise (p < 0.05) and lower estimated sweat rate (p < 0.001) were observed in N + ICE than N + AMB. Rate of Tgi rise was similar at low dose (p = 0.113) despite a lower estimated sweat rate in L + ICE than L+AMB (p < 0.01). Time-to-exhaustion was longer in L + ICE than L + AMB (p < 0.05), but similar between N + ICE and N + AMB (p = 0.142) and L + ICE and N + ICE (p = 0.766). [I-FABP] and [LPS] were similar (p > 0.05). CONCLUSIONS L + ICE elicited a lower heat dissipation compensatory effect with similar endurance capacity as N + ICE. Ice slurry conferred no protection against exertional heat stress-induced gastrointestinal perturbations.
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Affiliation(s)
- Sharifah B Alhadad
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Melissa C Y Chua
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jason K W Lee
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Heat Resilience and Performance Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; The N.1 Institute for Health, National University of Singapore, Singapore; Institute for Digital Medicine, National University of Singapore, Singapore
| | - Ivan C C Low
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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Heydenreich J, Koehler K, Braun H, Grosshauser M, Heseker H, Koenig D, Lampen A, Mosler S, Niess A, Schek A, Carlsohn A. Effects of internal cooling on physical performance, physiological and perceptional parameters when exercising in the heat: A systematic review with meta-analyses. Front Physiol 2023; 14:1125969. [PMID: 37113693 PMCID: PMC10126464 DOI: 10.3389/fphys.2023.1125969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/27/2023] [Indexed: 04/29/2023] Open
Abstract
Background: An elevated core temperature (Tcore) increases the risk of performance impairments and heat-related illness. Internal cooling (IC) has the potential to lower Tcore when exercising in the heat. The aim of the review was to systematically analyze the effects of IC on performance, physiological, and perceptional parameters. Methods: A systematic literature search was performed in the PubMed database on 17 December 2021. Intervention studies were included assessing the effects of IC on performance, physiological, or perceptional outcomes. Data extraction and quality assessment were conducted for the included literature. The standardized mean differences (SMD) and 95% Confidence Intervals (CI) were calculated using the inverse-variance method and a random-effects model. Results: 47 intervention studies involving 486 active subjects (13.7% female; mean age 20-42 years) were included in the meta-analysis. IC resulted in significant positive effects on time to exhaustion [SMD (95% CI) 0.40 (0.13; 0.67), p < 0.01]. IC significantly reduced Tcore [-0.19 (22120.34; -0.05), p < 0.05], sweat rate [-0.20 (-0.34; -0.06), p < 0.01], thermal sensation [-0.17 (-0.33; -0.01), p < 0.05], whereas no effects were found on skin temperature, blood lactate, and thermal comfort (p > 0.05). IC resulted in a borderline significant reduction in time trial performance [0.31 (-0.60; -0.02), p = 0.06], heart rate [-0.13 (-0.27; 0.01), p = 0.06], rate of perceived exertion [-0.16 (-0.31; -0.00), p = 0.05] and borderline increased mean power output [0.22 (0.00; 0.44), p = 0.05]. Discussion: IC has the potential to affect endurance performance and selected physiological and perceptional parameters positively. However, its effectiveness depends on the method used and the time point of administration. Future research should confirm the laboratory-based results in the field setting and involve non-endurance activities and female athletes. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022336623.
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Affiliation(s)
- Juliane Heydenreich
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Institute of Sports Sciences, Johannes Gutenberg-University of Mainz, Mainz, Germany
- *Correspondence: Juliane Heydenreich,
| | - Karsten Koehler
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Department of Sport and Health Sciences, Technical University of Munich, Munich, Germany
| | - Hans Braun
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Manfred Donike Institute for Doping Analysis, Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Mareike Grosshauser
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Olympic Center Rhineland-Palatinate/Saarland, Saarbrücken, Germany
| | - Helmut Heseker
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Institute of Nutrition, Consumption and Health, University of Paderborn, Paderborn, Germany
| | - Daniel Koenig
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Division of Sports Medicine, Exercise Physiology and Prevention, Center for Sport Science and University Sports, University of Vienna, Vienna, Austria
| | - Alfonso Lampen
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Risk Assessment Strategies, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Stephanie Mosler
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Olympic Center Stuttgart, Stuttgart, Germany
| | - Andreas Niess
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Department of Sports Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Alexandra Schek
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Editorial Team of the Journal Leistungssport, German Olympic Sports Confederation, Frankfurt, Germany
| | - Anja Carlsohn
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Department of Nutrition and Home Economics, University of Applied Science Hamburg, Hamburg, Germany
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Ingestion of carbonated water increases middle cerebral artery blood velocity and improves mood states in resting humans exposed to ambient heat stress. Physiol Behav 2022; 255:113942. [PMID: 35964802 DOI: 10.1016/j.physbeh.2022.113942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/02/2022] [Accepted: 08/10/2022] [Indexed: 11/21/2022]
Abstract
Sugar-free carbonated water is consumed worldwide. The consumption of carbonated water is high in summer, when the heat loss responses of sweating and skin vasodilation are activated, and thermal perceptions (thermal sensation and comfort) and mood states are negatively modulated. However, whether ingesting carbonated water under ambient heat exposure modulates cerebral blood flow index, heat loss responses, thermal perceptions, and mood states remains to be determined. In this study, 17 healthy, habitually active, young adults (eight women) ingested 4 °C noncarbonated or carbonated water under 37 °C ambient heat-stressed resting conditions. Both drinks increased the middle cerebral artery mean blood velocity, an index of cerebral blood flow, and mean arterial pressure, with carbonated water exhibiting higher elevations than noncarbonated water (P < 0.05). However, the heart rate, sweat rate, and skin blood flow during and after drinking remained unchanged between the two conditions (P > 0.05). The thermal sensation and comfort after drinking remained unchanged between the two conditions (P > 0.05); but, a drink-induced reduction in sleepiness was higher, and drink-induced elevations in motivation and exhilaration were higher after ingesting carbonated water than those after ingesting noncarbonated water (P < 0.05). The analyses suggest that in humans under ambient heat-stressed resting conditions, ingestion of cold carbonated water increases the cerebral blood flow index, blood pressure, motivation, and exhilaration, whereas it decreases sleepiness relative to ingestion of noncarbonated cold water. However, ingestion of cold carbonated water fails to modulate thermoregulatory responses and thermal perception as opposed to noncarbonated cold water.
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Roriz M, Brito P, Teixeira FJ, Brito J, Teixeira VH. Performance effects of internal pre- and per-cooling across different exercise and environmental conditions: A systematic review. Front Nutr 2022; 9:959516. [PMID: 36337635 PMCID: PMC9632747 DOI: 10.3389/fnut.2022.959516] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/19/2022] [Indexed: 11/13/2022] Open
Abstract
Exercise in a hot and humid environment may endanger athlete's health and affect physical performance. This systematic review aimed to examine whether internal administration of ice, cold beverages or menthol solutions may be beneficial for physical performance when exercising in different environmental conditions and sports backgrounds. A systematic search was performed in PubMed, Web of Science, Scopus and SPORTDiscus databases, from inception to April 2022, to identify studies meeting the following inclusion criteria: healthy male and female physically active individuals or athletes (aged ≥18 years); an intervention consisting in the internal administration (i.e., ingestion or mouth rinse) of ice slush, ice slurry or crushed ice and/or cold beverages and/or menthol solutions before and/or during exercise; a randomized crossover design with a control or placebo condition; the report of at least one physical performance outcome; and to be written in English. Our search retrieved 2,714 articles in total; after selection, 43 studies were considered, including 472 participants, 408 men and 64 women, aged 18-42 years, with a VO2max ranging from 46.2 to 67.2 mL⋅kg-1⋅min-1. Average ambient temperature and relative humidity during the exercise tasks were 32.4 ± 3.5°C (ranging from 22°C to 38°C) and 50.8 ± 13.4% (varying from 20.0% to 80.0%), respectively. Across the 43 studies, 7 exclusively included a menthol solution mouth rinse, 30 exclusively involved ice slurry/ice slush/crushed ice/cold beverages intake, and 6 examined both the effect of thermal and non-thermal internal techniques in the same protocol. Rinsing a menthol solution (0.01%) improved physical performance during continuous endurance exercise in the heat. Conversely, the ingestion of ice or cold beverages did not seem to consistently increase performance, being more likely to improve performance in continuous endurance trials, especially when consumed during exercises. Co-administration of menthol with or within ice beverages seems to exert a synergistic effect by improving physical performance. Even in environmental conditions that are not extreme, internal cooling strategies may have an ergogenic effect. Further studies exploring both intermittent and outdoor exercise protocols, involving elite male and female athletes and performed under not extreme environmental conditions are warranted. Systematic review registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021268197], identifier [CRD42021268197].
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Affiliation(s)
- Maria Roriz
- Faculty of Nutrition and Food Sciences, University of Porto (FCNAUP), Porto, Portugal
- Futebol Clube do Porto, Porto, Portugal
| | - Pedro Brito
- Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University of Maia, ISMAI, Maia, Portugal
| | - Filipe J. Teixeira
- Interdisciplinary Center for the Study of Human Performance (CIPER), Faculdade de Motricidade Humana, Universidade de Lisboa, Cruz-Quebrada, Portugal
- Atlântica, Instituto Universitário, Fábrica da Pólvora de Barcarena, Barcarena, Portugal
- Bettery Lifelab, Bettery S.A., Lisbon, Portugal
| | - João Brito
- Portugal Football School, Portuguese Football Federation, Oeiras, Portugal
| | - Vitor Hugo Teixeira
- Faculty of Nutrition and Food Sciences, University of Porto (FCNAUP), Porto, Portugal
- Futebol Clube do Porto, Porto, Portugal
- Research Centre in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sports, University of Porto (FADEUP), Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
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Naito T, Saito T, Morito A, Yamada S, Shimomasuda M, Nakamura M. Pre-cooling with ingesting a high-carbohydrate ice slurry on thermoregulatory responses and subcutaneous interstitial fluid glucose during heat exposure. J Physiol Anthropol 2022; 41:34. [PMID: 36217207 PMCID: PMC9549659 DOI: 10.1186/s40101-022-00309-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 09/28/2022] [Indexed: 11/07/2022] Open
Abstract
The purpose of this study was to compare the effects of ingesting ice slurries with two different carbohydrate contents on body temperatures and the subcutaneous interstitial fluid glucose level during heat exposure. Seven physically active men underwent one of three interventions: the ingestion of 7.5 g/kg of a control beverage (CON: 26°C), a normal-carbohydrate ice slurry (NCIS: −1°C), or a high-carbohydrate ice slurry (HCIS: −5°C). The participants were monitored for a 120-min period that included 10 min of rest, 25 min of exposure to the experimental cooling intervention (during which the beverage was ingested), and 85 min of seated rest in a climate chamber (36°C, 50% relative humidity). The rectal temperature in the HCIS and NCIS trials was lower than that in the CON trial from 40 to 75 min. The infrared tympanic temperature was also lower in the HCIS and NCIS trials than in the CON trial from 20 to 50 min, whereas the deep thigh or mean skin temperatures were not significantly different among the three groups. From 90 to 120 min, the subcutaneous interstitial fluid glucose level in the NCIS trial was lower than that at 65 min; however, reductions were not seen in the HCIS and CON trials. These findings suggest that both HCIS ingestion and conventional NCIS ingestion were effective cooling strategies for reducing thermal strain, while HCIS ingestion may also enable a higher subcutaneous interstitial fluid glucose level to be maintained, ensuring an adequate supply of required muscle substrates.
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Affiliation(s)
- Takashi Naito
- grid.419627.fDepartment of Sports Research, Japan Institute of Sports Sciences, 3-15-1 Nishigaoka Kita-ku, Tokyo, 115-0056 Japan ,grid.440874.b0000 0001 2183 8345Faculty of Law, Hokkai-Gakuen University, 4-1-40 Asahimachi Toyohira-ku, Sapporo City, Hokkaido 062-8605 Japan
| | - Tatsuya Saito
- grid.419627.fDepartment of Sports Research, Japan Institute of Sports Sciences, 3-15-1 Nishigaoka Kita-ku, Tokyo, 115-0056 Japan ,grid.265107.70000 0001 0663 5064Faculty of Medicine, Tottori University, 4-101 Koyamachominami, Tottori City, Tottori 683-8550 Japan
| | - Akihisa Morito
- grid.419836.10000 0001 2162 3360Health Science Research R&D Laboratories, Taisho Pharmaceutical Co., Ltd., 1-403 Yoshinomachi Kita-ku, Saitama City, Saitama 331-9530 Japan
| | - Satoshi Yamada
- grid.419836.10000 0001 2162 3360Health Science Research R&D Laboratories, Taisho Pharmaceutical Co., Ltd., 1-403 Yoshinomachi Kita-ku, Saitama City, Saitama 331-9530 Japan
| | - Masatsugu Shimomasuda
- grid.419836.10000 0001 2162 3360Research & Development Headquarters, Self-Medication, Taisho Pharmaceutical Co., Ltd., 3-24-1, Takada, Toshima-ku, Tokyo, 170-8633 Japan
| | - Mariko Nakamura
- grid.419627.fDepartment of Sports Research, Japan Institute of Sports Sciences, 3-15-1 Nishigaoka Kita-ku, Tokyo, 115-0056 Japan
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11
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Bayne F, Racinais S, Mileva KN, Hunter S, Gaoua N. The Type of Per-Cooling Strategies Currently Employed by Competitive and Professional Cyclists-Triathletes During Training and Competition Are Condition (Dry vs. Humid) Dependant. Front Sports Act Living 2022; 4:845427. [PMID: 35694320 PMCID: PMC9174669 DOI: 10.3389/fspor.2022.845427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/21/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose To investigate cooling strategies employed by athletes (cyclists-triathletes) during training and competition in hot and dry (HD) and hot and humid (HH) conditions. Methods Thirty-five athletes completed an online questionnaire on the type, timing, and justification of cooling strategies employed during past training and/or competitions in HD and HH conditions. In addition, 3 athletes also completed a one-to-one follow-up interview. Results Comparisons between strategies employed in all conditions were based on N = 14 (40%). Cold-water pouring was the most employed (N = 4; 21%) strategy during training and/or competing in hot conditions. The timing of the strategies employed was based on pitstops only (N = 7; 50%). The justification for strategies employed was based on trial and error (N = 9, 42.85%: N = 10, 47.61%). All athletes rated strategies employed as 1 (“not effective for minimising performance impairments and heat-related illnesses”). Comparisons between HD and HH were based on N = 21 (60%), who employed different strategies based on condition. Cold-water ingestion was the most employed (N = 9, 43%) strategy in HD, whereas a combination of cold-water ingestion and pouring was the most employed (N = 9, 43%) strategy in HH. The timing of strategies employed in the HD split was pre-planned by distance but was modified based on how athletes felt during (N = 8, 38%), and pre-planned by distance and pit stops (N = 8, 38%). The timing of strategies employed in HH was pre-planned based on distance and how athletes felt during (N = 9, 42%). About 57% (N = 12) of the 60% (N = 21) perceived effectiveness in HD and HH as 3 (“Sometimes effective and sometimes not effective”), whereas 43% (N = 9) of the 60% (N = 21) perceived effectiveness in HD and HH as 4 (“Effective for minimising performance impairments”). Conclusion Cold-water ingestion is the preferred strategy by athletes in HD compared to a combination of cold-water ingestion and pouring in HH conditions. All strategies were pre-planned and trialled based on distance and how athletes felt during training and/or competition. These strategies were perceived as effective for minimising performance impairments, but not heat-related illnesses. Future studies should evaluate the effectiveness of these cooling strategies on performance and thermoregulatory responses in HD and HH conditions.
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Affiliation(s)
- Freya Bayne
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
- *Correspondence: Freya Bayne
| | | | - Katya N. Mileva
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - Steve Hunter
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - Nadia Gaoua
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
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Ice Slurry Ingestion Lowers Thermoregulatory Strain in Wheelchair Tennis Players During Repeated Sprint Intervals in the Heat. Int J Sports Physiol Perform 2022; 17:1748-1755. [DOI: 10.1123/ijspp.2022-0174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/27/2022] [Accepted: 08/26/2022] [Indexed: 11/15/2022]
Abstract
Purpose: To examine the efficacy of per-cooling via ice slurry ingestion (ICE) in wheelchair tennis players exercising in the heat. Method: Eight wheelchair tennis players undertook sprints (4 sets of 10 × 5 s over 40 min) in a hot environment (∼32 °C), interspersed by 3 boluses of 2.67 g·kg (6.8 g·kg total) ICE or drinking temperate water (control condition). Athletes performed an on-court test of repeated sprint ability (20 × 20 m) in temperate conditions immediately before and 20 minutes after the heat exposure, and time to complete each sprint as well as intermediate times were recorded. Gastrointestinal and weighted mean skin and forehead temperatures were collected throughout the heat exposure, as were thermal sensation, heart rate, and blood lactate concentration. Sweat rate was calculated from body mass changes and fluid/ice intakes. Results: Compared with the control condition, ICE resulted in a significantly lower gastrointestinal temperature (95% CI, 0.11–0.17 °C; P < .001), forehead temperature (0.58–1.06 °C; P < .001), thermal sensation (0.07–0.50 units; P = .017), and sweat rate (0.06–0.46 L·h−1; P = .017). Skin temperature, heart rate, and blood lactate concentration were not significantly different between conditions (P ≥ .598). There was no overall change preheating to postheating (P ≥ .114) or an effect of condition (P ≥ .251) on repeated sprint times. Conclusions: ICE is effective at lowering objective and subjective thermal strain when consumed between sets of repeated wheelchair sprints in the heat. However, ICE has no effect on on-court repeated 20-m sprint performance.
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13
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Lei TH, Wang F. Looking ahead of 2021 Tokyo Summer Olympic Games: How Does Humid Heat Affect Endurance Performance? Insight into physiological mechanism and heat-related illness prevention strategies. J Therm Biol 2021; 99:102975. [PMID: 34420619 DOI: 10.1016/j.jtherbio.2021.102975] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/25/2022]
Abstract
The combination of high humidity and ambient temperature of the 2021 Tokyo Summer Olympic Game will undoubtfully result in greater physiological strains and thereby downregulates the endurance performance of athletes. Although many research studies have highlighted that the thermoregulatory strain is greater when the environment is hot and humid, no review articles have addressed the thermoregulatory and performance differences between dry and humid heat and such lack of consensuses in this area will lead to increase the risk of heat-related injuries as well as suboptimal preparation. Furthermore, specific strategies to counteract this stressful environment has not been outlined in the current literature. Therefore, the purposes of this review are: 1) to provide a clear evidence that humid heat is more stressful than dry heat for both male and female athletes and therefore the preparation for the Tokyo Summer Olympic should be environmental specific instead of a one size fits all approach; 2) to highlight why female athletes may be facing a disadvantage when performing a prolonged endurance event under high humidity environment and 3) to highlight the potential interventional strategies to reduce thermal strain in hot-humid environment. The summaries of this review are: both male and female should be aware of the environmental condition in Tokyo as humid heat is more stressful than dry heat; Short-term heat acclimation may not elicit proper thermoregulatory adaptations in hot-humid environment; cold water immersion with proper hydration and some potential per-cooling modalities may be beneficial for both male and female athletes in hot-humid environment.
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Affiliation(s)
- Tze-Huan Lei
- College of Physical Education, Hubei Normal University, Huangshi, China
| | - Faming Wang
- School of Architecture and Art, Central South University, Changsha, China.
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14
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Jay O, Capon A, Berry P, Broderick C, de Dear R, Havenith G, Honda Y, Kovats RS, Ma W, Malik A, Morris NB, Nybo L, Seneviratne SI, Vanos J, Ebi KL. Reducing the health effects of hot weather and heat extremes: from personal cooling strategies to green cities. Lancet 2021; 398:709-724. [PMID: 34419206 DOI: 10.1016/s0140-6736(21)01209-5] [Citation(s) in RCA: 127] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 12/19/2020] [Accepted: 05/20/2021] [Indexed: 01/01/2023]
Abstract
Heat extremes (ie, heatwaves) already have a serious impact on human health, with ageing, poverty, and chronic illnesses as aggravating factors. As the global community seeks to contend with even hotter weather in the future as a consequence of global climate change, there is a pressing need to better understand the most effective prevention and response measures that can be implemented, particularly in low-resource settings. In this Series paper, we describe how a future reliance on air conditioning is unsustainable and further marginalises the communities most vulnerable to the heat. We then show that a more holistic understanding of the thermal environment at the landscape and urban, building, and individual scales supports the identification of numerous sustainable opportunities to keep people cooler. We summarise the benefits (eg, effectiveness) and limitations of each identified cooling strategy, and recommend optimal interventions for settings such as aged care homes, slums, workplaces, mass gatherings, refugee camps, and playing sport. The integration of this information into well communicated heat action plans with robust surveillance and monitoring is essential for reducing the adverse health consequences of current and future extreme heat.
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Affiliation(s)
- Ollie Jay
- Thermal Ergonomics Laboratory, The University of Sydney, Sydney, NSW, Australia; Sydney School of Health Sciences, The University of Sydney, Sydney, NSW, Australia; Sydney School of Public Health, The University of Sydney, Sydney, NSW, Australia; Faculty of Medicine and Health, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia.
| | - Anthony Capon
- Sydney School of Public Health, The University of Sydney, Sydney, NSW, Australia; Monash Sustainable Development Institute, Monash University, Melbourne, VIC, Australia
| | - Peter Berry
- Faculty of Environment, University of Waterloo, ON, Canada
| | - Carolyn Broderick
- School of Medical Sciences, UNSW Medicine, Sydney, UNSW, Australia; The Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Richard de Dear
- Indoor Environmental Quality Laboratory, School of Architecture, Design, and Planning, The University of Sydney, Sydney, NSW, Australia
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, UK
| | - Yasushi Honda
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - R Sari Kovats
- NIHR Health Protection Research Unit in Environmental Change and Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Wei Ma
- School of Public Health, Shandong University, Jinan, China; Climate Change and Health Center, Shandong University, Jinan, China
| | - Arunima Malik
- School of Physics, Faculty of Science, ISA, The University of Sydney, Sydney, NSW, Australia; Discipline of Accounting, Business School, The University of Sydney, Sydney, NSW, Australia
| | - Nathan B Morris
- Thermal Ergonomics Laboratory, The University of Sydney, Sydney, NSW, Australia; Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Lars Nybo
- Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Sonia I Seneviratne
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
| | - Jennifer Vanos
- School of Sustainability, Arizona State University, AZ, USA
| | - Kristie L Ebi
- Center for Health and the Global Environment, University of Washington, WA, USA
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15
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Morrissey MC, Casa DJ, Brewer GJ, Adams WM, Hosokawa Y, Benjamin CL, Grundstein AJ, Hostler D, McDermott BP, McQuerry ML, Stearns RL, Filep EM, DeGroot DW, Fulcher J, Flouris AD, Huggins RA, Jacklitsch BL, Jardine JF, Lopez RM, McCarthy RB, Pitisladis Y, Pryor RR, Schlader ZJ, Smith CJ, Smith DL, Spector JT, Vanos JK, Williams WJ, Vargas NT, Yeargin SW. Heat Safety in the Workplace: Modified Delphi Consensus to Establish Strategies and Resources to Protect the US Workers. GEOHEALTH 2021; 5:e2021GH000443. [PMID: 34471788 PMCID: PMC8388206 DOI: 10.1029/2021gh000443] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/08/2021] [Accepted: 06/11/2021] [Indexed: 06/04/2023]
Abstract
The purpose of this consensus document was to develop feasible, evidence-based occupational heat safety recommendations to protect the US workers that experience heat stress. Heat safety recommendations were created to protect worker health and to avoid productivity losses associated with occupational heat stress. Recommendations were tailored to be utilized by safety managers, industrial hygienists, and the employers who bear responsibility for implementing heat safety plans. An interdisciplinary roundtable comprised of 51 experts was assembled to create a narrative review summarizing current data and gaps in knowledge within eight heat safety topics: (a) heat hygiene, (b) hydration, (c) heat acclimatization, (d) environmental monitoring, (e) physiological monitoring, (f) body cooling, (g) textiles and personal protective gear, and (h) emergency action plan implementation. The consensus-based recommendations for each topic were created using the Delphi method and evaluated based on scientific evidence, feasibility, and clarity. The current document presents 40 occupational heat safety recommendations across all eight topics. Establishing these recommendations will help organizations and employers create effective heat safety plans for their workplaces, address factors that limit the implementation of heat safety best-practices and protect worker health and productivity.
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Affiliation(s)
- Margaret C. Morrissey
- Department of KinesiologyKorey Stringer InstituteUniversity of ConnecticutMansfieldCTUSA
| | - Douglas J. Casa
- Department of KinesiologyKorey Stringer InstituteUniversity of ConnecticutMansfieldCTUSA
| | - Gabrielle J. Brewer
- Department of KinesiologyKorey Stringer InstituteUniversity of ConnecticutMansfieldCTUSA
| | - William M. Adams
- Department of KinesiologyUniversity of North Carolina at GreensboroGreensboroNCUSA
| | - Yuri Hosokawa
- Faculty of Sports SciencesWaseda UniversitySaitamaJapan
| | | | | | - David Hostler
- Department of Exercise and Nutrition SciencesCenter for Research and Education in Special EnvironmentsBuffaloNYUSA
| | - Brendon P. McDermott
- Department of Health, Human Performance and RecreationUniversity of ArkansasFayettevilleARUSA
| | | | - Rebecca L. Stearns
- Department of KinesiologyKorey Stringer InstituteUniversity of ConnecticutMansfieldCTUSA
| | - Erica M. Filep
- Department of KinesiologyKorey Stringer InstituteUniversity of ConnecticutMansfieldCTUSA
| | - David W. DeGroot
- Fort Benning Heat CenterMartin Army Community HospitalFort BenningGAUSA
| | | | - Andreas D. Flouris
- Department of Exercise ScienceFAME LaboratoryUniversity of ThessalyTrikalaGreece
| | - Robert A. Huggins
- Department of KinesiologyKorey Stringer InstituteUniversity of ConnecticutMansfieldCTUSA
| | | | - John F. Jardine
- Department of KinesiologyKorey Stringer InstituteUniversity of ConnecticutMansfieldCTUSA
| | - Rebecca M. Lopez
- School of Physical Therapy & Rehabilitation SciencesMorsani College of MedicineUniversity of South FloridaTampaFLUSA
| | | | - Yannis Pitisladis
- Collaborating Centre of Sports MedicineUniversity of BrightonBrightonUK
| | - Riana R. Pryor
- Department of Exercise and Nutrition SciencesCenter for Research and Education in Special EnvironmentsBuffaloNYUSA
| | - Zachary J. Schlader
- Department of KinesiologySchool of Public HealthIndiana UniversityBloomingtonIAUSA
| | - Caroline J. Smith
- Department of Health and Exercise ScienceAppalachian State UniversityBooneNCUSA
| | - Denise L. Smith
- Department of Health and Human Physiological SciencesFirst Responder Health and Safety LaboratorySkidmore CollegeSaratoga SpringsNYUSA
| | - June T. Spector
- Department of Environmental and Occupational Health SciencesSchool of Public HealthUniversity of WashingtonSeattleWAUSA
| | | | - W. Jon Williams
- Centers for Disease Control and Prevention (CDC)National Personal Protective Technology Laboratory (NPPTL)National Institute for Occupational Safety and Health (NIOSH)PittsburghPAUSA
| | - Nicole T. Vargas
- Faculty of Health SciencesUniversity of SydneySydneyNSWAustralia
| | - Susan W. Yeargin
- Department of Exercise ScienceArnold School of Public HealthUniversity of South CarolinaColumbiaSCUSA
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16
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Ioannou LG, Mantzios K, Tsoutsoubi L, Nintou E, Vliora M, Gkiata P, Dallas CN, Gkikas G, Agaliotis G, Sfakianakis K, Kapnia AK, Testa DJ, Amorim T, Dinas PC, Mayor TS, Gao C, Nybo L, Flouris AD. Occupational Heat Stress: Multi-Country Observations and Interventions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:6303. [PMID: 34200783 PMCID: PMC8296111 DOI: 10.3390/ijerph18126303] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/25/2021] [Accepted: 06/07/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND Occupational heat exposure can provoke health problems that increase the risk of certain diseases and affect workers' ability to maintain healthy and productive lives. This study investigates the effects of occupational heat stress on workers' physiological strain and labor productivity, as well as examining multiple interventions to mitigate the problem. METHODS We monitored 518 full work-shifts obtained from 238 experienced and acclimatized individuals who work in key industrial sectors located in Cyprus, Greece, Qatar, and Spain. Continuous core body temperature, mean skin temperature, heart rate, and labor productivity were collected from the beginning to the end of all work-shifts. RESULTS In workplaces where self-pacing is not feasible or very limited, we found that occupational heat stress is associated with the heat strain experienced by workers. Strategies focusing on hydration, work-rest cycles, and ventilated clothing were able to mitigate the physiological heat strain experienced by workers. Increasing mechanization enhanced labor productivity without increasing workers' physiological strain. CONCLUSIONS Empowering laborers to self-pace is the basis of heat mitigation, while tailored strategies focusing on hydration, work-rest cycles, ventilated garments, and mechanization can further reduce the physiological heat strain experienced by workers under certain conditions.
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Affiliation(s)
- Leonidas G. Ioannou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, 2100 Copenhagen, Denmark;
| | - Konstantinos Mantzios
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Lydia Tsoutsoubi
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Eleni Nintou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Maria Vliora
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Paraskevi Gkiata
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Constantinos N. Dallas
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Giorgos Gkikas
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Gerasimos Agaliotis
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Kostas Sfakianakis
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Areti K. Kapnia
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Davide J. Testa
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Tânia Amorim
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Petros C. Dinas
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
| | - Tiago S. Mayor
- SIMTECH Laboratory, Transport Phenomena Research Centre, Engineering Faculty of Porto University, 4200-465 Porto, Portugal;
| | - Chuansi Gao
- Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, 22100 Lund, Sweden;
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, 2100 Copenhagen, Denmark;
| | - Andreas D. Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece; (L.G.I.); (K.M.); (L.T.); (E.N.); (M.V.); (P.G.); (C.N.D.); (G.G.); (G.A.); (K.S.); (A.K.K.); (D.J.T.); (T.A.); (P.C.D.)
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17
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Périard JD, Eijsvogels TMH, Daanen HAM. Exercise under heat stress: thermoregulation, hydration, performance implications, and mitigation strategies. Physiol Rev 2021; 101:1873-1979. [PMID: 33829868 DOI: 10.1152/physrev.00038.2020] [Citation(s) in RCA: 138] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A rise in body core temperature and loss of body water via sweating are natural consequences of prolonged exercise in the heat. This review provides a comprehensive and integrative overview of how the human body responds to exercise under heat stress and the countermeasures that can be adopted to enhance aerobic performance under such environmental conditions. The fundamental concepts and physiological processes associated with thermoregulation and fluid balance are initially described, followed by a summary of methods to determine thermal strain and hydration status. An outline is provided on how exercise-heat stress disrupts these homeostatic processes, leading to hyperthermia, hypohydration, sodium disturbances, and in some cases exertional heat illness. The impact of heat stress on human performance is also examined, including the underlying physiological mechanisms that mediate the impairment of exercise performance. Similarly, the influence of hydration status on performance in the heat and how systemic and peripheral hemodynamic adjustments contribute to fatigue development is elucidated. This review also discusses strategies to mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat by examining the benefits of heat acclimation, cooling strategies, and hyperhydration. Finally, contemporary controversies are summarized and future research directions are provided.
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Affiliation(s)
- Julien D Périard
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australia
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hein A M Daanen
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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18
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Naito T, Haramura M, Muraishi K, Yamazaki M, Takahashi H. Cooling during short-term heat acclimation enhances aerobic capacity but not sweat capacity. Eur J Sport Sci 2021; 22:579-588. [PMID: 33522891 DOI: 10.1080/17461391.2021.1884751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
To characterize the adaptive responses to short-term heat acclimation (HA) training with repeated-sprint exercises and to determine the effects of ice slurry ingestion during HA on aerobic capacity and adaptations. Seven physically active males completed two 5 consecutive day interventions in a randomized cross-over design. Participants performed approximately 80-min intermittent repeated-sprints using a cycling ergometer including break-time and half time in 36.5°C and 50%RH. Participants ingested either 1.25 g·kg body mass-1 of ice slurry (ICE: -1°C) or room temperature beverage (NOC: 36.5°C) throughout each break and 7.5 g·kg body mass-1 of the same drink during half time. Maximum oxygen uptake (V˙O2max) test in hot conditions was completed before and after HA training. Ice slurry ingestion during short-term HA training induced significantly higher both V˙O2max and watt at V˙O2max following HA training. Total work done was significantly higher in HA with ICE than for the NOC trial on both day 1 and day 5. Sweating Na+ concentration in NOC trial at day 5 were significantly lower than those in the NOC trial day 1, but was not observed in ICE trial. Cooling during HA training may be an effective strategy for enhancement of aerobic capacity via the adaptations gained from a higher quantity of exercise caused by cooling, but does not improve heat loss capacity. HighlightsThere is the potential dilemma whether cooling during short-term training in the heat might negatively impacts the process of helping athletes adapt to hot environments.Cooling during short-term heat training may be an effective strategy to enhancement of aerobic capacity via the adaptations gained from a higher quantity of exercise caused by cooling, but does not improve heat loss capacity.The study suggests the importance to selecting cooling during the heat acclimation phase of consecutive field training according to the individual's training plan.
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Affiliation(s)
- Takashi Naito
- Department of Sports Research, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Miki Haramura
- Department of Sports Sciences, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Koji Muraishi
- Japan Sport Council, Tokyo, Japan.,Graduate School of Community and Human Services, Rikkyo University, Saitama, Japan
| | - Misa Yamazaki
- Department of Sports Sciences, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Hideyuki Takahashi
- Department of Sports Research, Japan Institute of Sports Sciences, Tokyo, Japan.,Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
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19
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Racinais S, Ihsan M, Taylor L, Cardinale M, Adami PE, Alonso JM, Bouscaren N, Buitrago S, Esh CJ, Gomez-Ezeiza J, Garrandes F, Havenith G, Labidi M, Lange G, Lloyd A, Moussay S, Mtibaa K, Townsend N, Wilson MG, Bermon S. Hydration and cooling in elite athletes: relationship with performance, body mass loss and body temperatures during the Doha 2019 IAAF World Athletics Championships. Br J Sports Med 2021; 55:1335-1341. [PMID: 33579722 PMCID: PMC8606454 DOI: 10.1136/bjsports-2020-103613] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2021] [Indexed: 11/09/2022]
Abstract
Purpose To characterise hydration, cooling, body mass loss, and core (Tcore) and skin (Tsk) temperatures during World Athletics Championships in hot-humid conditions. Methods Marathon and race-walk (20 km and 50 km) athletes (n=83, 36 women) completed a pre-race questionnaire. Pre-race and post-race body weight (n=74), Tcore (n=56) and Tsk (n=49; thermography) were measured. Results Most athletes (93%) had a pre-planned drinking strategy (electrolytes (83%), carbohydrates (81%)) while ice slurry was less common (11%; p<0.001). More men than women relied on electrolytes and carbohydrates (91%–93% vs 67%–72%, p≤0.029). Drinking strategies were based on personal experience (91%) rather than external sources (p<0.001). Most athletes (80%) planned pre-cooling (ice vests (53%), cold towels (45%), neck collars (21%) and ice slurry (21%)) and/or mid-cooling (93%; head/face dousing (65%) and cold water ingestion (52%)). Menthol usage was negligible (1%–2%). Pre-race Tcore was lower in athletes using ice vests (37.5°C±0.4°C vs 37.8°C±0.3°C, p=0.024). Tcore (pre-race 37.7°C±0.3°C, post-race 39.6°C±0.6°C) was independent of event, ranking or performance (p≥0.225). Pre-race Tsk was correlated with faster race completion (r=0.32, p=0.046) and was higher in non-finishers (did not finish (DNF); 33.8°C±0.9°C vs 32.6°C±1.4°C, p=0.017). Body mass loss was higher in men than women (−2.8±1.5% vs −1.3±1.6%, p<0.001), although not associated with performance. Conclusion Most athletes’ hydration strategies were pre-planned based on personal experience. Ice vests were the most adopted pre-cooling strategy and the only one minimising Tcore, suggesting that event organisers should be cognisant of logistics (ie, freezers). Dehydration was moderate and unrelated to performance. Pre-race Tsk was related to performance and DNF, suggesting that Tsk modulation should be incorporated into pre-race strategies.
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Affiliation(s)
- Sebastien Racinais
- Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
| | - Mohammed Ihsan
- Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
- Human Potential Translational Research Program, NUS Yong Loo Lin School of Medicine, Singapore
| | - Lee Taylor
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
- Human Performance Research Centre, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Marco Cardinale
- Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
- Institute of Sport Exercise and Health (ISEH), University College London, London, UK
| | | | - Juan Manuel Alonso
- Sports Medicine, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
| | | | | | - Chris J Esh
- Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Josu Gomez-Ezeiza
- Institute of Sport and Exercise Medicine, Stellenbosch University Faculty of Medicine and Health Sciences, Cape Town, Western Cape, South Africa
| | | | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, Leics, UK
| | - Mariem Labidi
- Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
| | - Gunter Lange
- Health and Science Department, World Athletics, Monaco
| | - Alexander Lloyd
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, Leics, UK
| | - Sebastien Moussay
- Normandie Univ, UNICAEN, INSERM, COMETE, CYCERON, CHU Caen, Caen, Normandie, France
| | - Khouloud Mtibaa
- Physical Education Department, College of Education, Qatar University, Doha, Qatar
| | - Nathan Townsend
- Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Ad Dawhah, Qatar
| | - Mathew G Wilson
- Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
- Institute of Sport Exercise and Health (ISEH), University College London, London, UK
| | - Stephane Bermon
- Health and Science Department, World Athletics, Monaco
- Human Motricity Laboratory Expertise Sport Health, Cote d'Azur University, Nice, Provence-Alpes-Côte d'Azu, France
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20
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The Effect of Upper-Body Positioning on the Aerodynamic–Physiological Economy of Time-Trial Cycling. Int J Sports Physiol Perform 2021; 16:51-58. [DOI: 10.1123/ijspp.2019-0547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 11/18/2022]
Abstract
Purpose: Cycling time trials (TTs) are characterized by riders’ adopting aerodynamic positions to lessen the impact of aerodynamic drag on velocity. The optimal performance requirements for TTs likely exist on a continuum of rider aerodynamics versus physiological optimization, yet there is little empirical evidence to inform riders and coaches. The aim of the present study was to investigate the relationship between aerodynamic optimization, energy expenditure, heat production, and performance. Methods: Eleven trained cyclists completed 5 submaximal exercise tests followed by a TT. Trials were completed at hip angles of 12° (more horizontal), 16°, 20°, 24° (more vertical), and their self-selected control position. Results: The largest decrease in power output at anaerobic threshold compared with control occurred at 12° (−16 [20] W, P = .03; effect size [ES] = 0.8). There was a linear relationship between upper-body position and heat production (R2 = .414, P = .04) but no change in mean body temperature, suggesting that, as upper-body position and hip angle increase, convective and evaporative cooling also rise. The highest aerodynamic–physiological economy occurred at 12° (384 [53] W·CdA−1·L−1·min−1, ES = 0.4), and the lowest occurred at 24° (338 [28] W·CdA−1·L−1·min−1, ES = 0.7), versus control (367 [41] W·CdA−1·L−1·min−1). Conclusion: These data suggest that the physiological cost of reducing hip angle is outweighed by the aerodynamic benefit and that riders should favor aerodynamic optimization for shorter TT events. The impact on thermoregulation and performance in the field requires further investigation.
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21
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Onitsuka S, Zheng X, Hasegawa H. Ice slurry ingestion before and during exercise inhibit the increase in core and deep-forehead temperatures in the second half of the exercise in a hot environment. J Therm Biol 2020; 94:102760. [PMID: 33293001 DOI: 10.1016/j.jtherbio.2020.102760] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/12/2020] [Accepted: 10/05/2020] [Indexed: 10/23/2022]
Abstract
Many studies have reported that pre-exercise ice slurry ingestion improves exercise performance; however, it may increase the risk of developing heat stroke. Some studies have suggested that pre-exercise ice slurry ingestion accelerates the core temperature increase that occurs during exercise. Therefore, this study aimed to investigate whether the ingestion of ice slurry before and during exercise can inhibit this acceleration. Moreover, we measured the deep-forehead temperature (Tdeep head) to determine whether ice slurry ingestion before and during exercise can maintain this reduction in brain temperature. Eleven male participants at room temperature (24 °C, 50% relative humidity [RH]) ingested 7.5 g/kg of ice slurry or a thermoneutral sports drink within 30 min. They then exercised for approximately 60 min at 50% of the maximal oxygen uptake in a hot environment (34 °C, 50% RH) while ingesting 1.25 g/kg of ice slurry or a thermoneutral sports drink every 10 min. Rectal temperature (Tre), Tdeep head, forehead skin temperature, mean skin temperature, heart rate, nude body mass, and urine specific gravity were measured as physiological indices. The rating of perceived exertion, thermal sensation, and thermal comfort were measured at 5-min intervals throughout the experiment. The Tre and Tdeep head during the second half of the exercise session were significantly reduced after ingestion of the ice slurry before and during exercise (p < 0.05). In addition, the rate of increase in Tre and Tdeephead slowed during the second half of the exercise session after the ingestion of the ice slurry before and during exercise (p < 0.05). These results indicate that the increases in Tre and Tdeep head, reflecting brain temperature in the second half of the exercise session, were significantly inhibited by ice slurry ingestion before and during exercise.
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Affiliation(s)
- Sumire Onitsuka
- Faculty of Human Health Science, Hiroshima Bunka Gakuen University, Japan.
| | - Xinyan Zheng
- Department of Sport Science, Shanghai University of Sport, Shanghai, China
| | - Hiroshi Hasegawa
- Graduate School of Humanities and Social Sciences, Hiroshima University, Japan
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22
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Iwata R, Kawamura T, Hosokawa Y, Chang L, Suzuki K, Muraoka I. Differences between sexes in thermoregulatory responses and exercise time during endurance exercise in a hot environment following pre-cooling with ice slurry ingestion. J Therm Biol 2020; 94:102746. [PMID: 33292987 DOI: 10.1016/j.jtherbio.2020.102746] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/23/2020] [Accepted: 09/29/2020] [Indexed: 12/14/2022]
Abstract
This study aimed to examine differences between sexes in thermoregulatory responses and exercise time after ice slurry ingestion in a hot environment. Twenty-four healthy adults (male n = 12, body weight (BW) = 65.8 ± 10.3; female n = 12, BW = 58.2 ± 10.0) ingested 7.5 g/kg of either ice slurry at -1 °C (ICE) or control water at 20 °C (CON) before cycling at 55%VO2 max in a hot environment (controlled at 38 °C, 40% relative humidity). Rectal (Tre) and skin (Tsk) temperature, heart rate, sweat rate, respiratory gases, ratings of thermal sensation (TS), thermal comfort (TC), and rating of perceived exertion (RPE) were measured. Ice slurry did not improve exercise time in both sexes despite Tre was significantly lower in ICE than CON in both sexes. Tre, Tsk, HR, sweat rate and TS did not differ between sexes. TC and RPE in ICE were significantly higher during exercise in males than in females. In conclusion, there were no sex differences in the effects of pre-cooling with ice slurry ingestion; however, pre-cooling with ice slurry may be more effective in mitigating ratings of TC and RPE in females than males.
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Affiliation(s)
- Risa Iwata
- Waseda University, Graduate School of Sport Sciences, Saitama, Japan.
| | - Takuji Kawamura
- Waseda University, Faculty of Sport Sciences, Saitama, Japan
| | - Yuri Hosokawa
- Waseda University, Faculty of Sport Sciences, Saitama, Japan
| | - Lili Chang
- Waseda University, Graduate School of Sport Sciences, Saitama, Japan
| | | | - Isao Muraoka
- Waseda University, Faculty of Sport Sciences, Saitama, Japan
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23
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Morris NB, Jay O, Flouris AD, Casanueva A, Gao C, Foster J, Havenith G, Nybo L. Sustainable solutions to mitigate occupational heat strain - an umbrella review of physiological effects and global health perspectives. Environ Health 2020; 19:95. [PMID: 32887627 PMCID: PMC7487490 DOI: 10.1186/s12940-020-00641-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/12/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND Climate change is set to exacerbate occupational heat strain, the combined effect of environmental and internal heat stress on the body, threatening human health and wellbeing. Therefore, identifying effective, affordable, feasible and sustainable solutions to mitigate the negative effects on worker health and productivity, is an increasingly urgent need. OBJECTIVES To systematically identify and evaluate methods that mitigate occupational heat strain in order to provide scientific-based guidance for practitioners. METHODS An umbrella review was conducted in biomedical databases employing the following eligibility criteria: 1) ambient temperatures > 28 °C or hypohydrated participants, 2) healthy adults, 3) reported psychophysiological (thermal comfort, heart rate or core temperature) and/or performance (physical or cognitive) outcomes, 4) written in English, and 5) published before November 6, 2019. A second search for original research articles was performed to identify interventions of relevance but lacking systematic reviews. All identified interventions were independently evaluated by all co-authors on four point scales for effectiveness, cost, feasibility and environmental impact. RESULTS Following screening, 36 systematic reviews fulfilled the inclusion criteria. The most effective solutions at mitigating occupational heat strain were wearing specialized cooling garments, (physiological) heat acclimation, improving aerobic fitness, cold water immersion, and applying ventilation. Although air-conditioning and cooling garments in ideal settings provide best scores for effectiveness, the limited applicability in certain industrial settings, high economic cost and high environmental impact are drawbacks for these solutions. However, (physiological) acclimatization, planned breaks, shading and optimized clothing properties are attractive alternative solutions when economic and ecological sustainability aspects are included in the overall evaluation. DISCUSSION Choosing the most effective solution or combinations of methods to mitigate occupational heat strain will be scenario-specific. However, this paper provides a framework for integrating effectiveness, cost, feasibility (indoors and outdoor) and ecologic sustainability to provide occupational health and safety professionals with evidence-based guidelines.
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Affiliation(s)
- Nathan B. Morris
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Denmark
| | - Ollie Jay
- Thermal Ergonomics Laboratory, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Andreas D. Flouris
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Ana Casanueva
- Federal Office of Meteorology and Climatology, MeteoSwiss, Zurich Airport, Zurich, Switzerland
- Meteorology Group, Department of Applied Mathematics and Computer Sciences, University of Cantabria, Santander, Spain
| | - Chuansi Gao
- Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Lund, Sweden
| | - Josh Foster
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Denmark
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24
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Bongers CCWG, de Korte JQ, Eijsvogels T. Infographic. Keep it cool and beat the heat: cooling strategies for exercise in hot and humid conditions. Br J Sports Med 2020; 55:bjsports-2020-102294. [PMID: 32561517 DOI: 10.1136/bjsports-2020-102294] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2020] [Indexed: 11/03/2022]
Affiliation(s)
- Coen C W G Bongers
- Radboud Institute for Health Sciences, Department of Physiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Johannus Q de Korte
- Radboud Institute for Health Sciences, Department of Physiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Thijs Eijsvogels
- Radboud Institute for Health Sciences, Department of Physiology, Radboud university medical center, Nijmegen, The Netherlands
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25
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Naito T, Haramura M, Muraishi K, Yamazaki M, Takahashi H. Impact of Ice Slurry Ingestion During Break-Times on Repeated-Sprint Exercise in the Heat. Sports Med Int Open 2020; 4:E45-E52. [PMID: 32395608 PMCID: PMC7205515 DOI: 10.1055/a-1139-1761] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/20/2020] [Accepted: 03/08/2020] [Indexed: 10/26/2022] Open
Abstract
The study aimed to investigate the effects of ice slurry ingestion during break times and half-time (HT) on repeated-sprint performance and core temperature in the heat. Seven males performed two different trials as follows: ice slurry (-1°C) or room temperature water ingestion at each break and HT break at 36.5°C, 50% relative humidity. Participants performed 30 sets of 1-min periods of repeated- sprint exercises protocol using a cycling ergometer. Each period consisted of 5 sec of maximal pedaling, 25 sec of pedaling with no workload, and 30 sec of rest; two sets of exercise periods were separated by 10 min of rest. Each break was implemented for 1 min after every 5 sets. The rectal temperature in ice slurry ingestion was significantly lower than that of the room temperature water at 45 set (p=0.04). Total and mean work done was greater in ice slurry ingestion compared to room temperature water ingestion (p < 0.05). These results suggested that ice slurry ingestion during break times and HT break may be an effective cooling strategy to attenuate the rise of core temperature in the second half of exercise and improve the repeated-sprint exercise capacity in the heat.
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Affiliation(s)
- Takashi Naito
- Department of Sports Research, Japan Institute of Sports Sciences, Kita-ku, Japan
| | - Miki Haramura
- Faculty of Sport Sciences, Waseda University, Shinjuku-ku,Japan.,Department of Sports Sciences, Japan Institute of Sports Sciences, Kita-ku, Japan
| | - Koji Muraishi
- Department of Sports Sciences, Japan Institute of Sports Sciences, Kita-ku, Japan.,Graduate School of Community and Health Services, Rikkyo University, Niiza-city, Japan
| | - Misa Yamazaki
- Department of Sports Sciences, Japan Institute of Sports Sciences, Kita-ku, Japan
| | - Hideyuki Takahashi
- Department of Sports Research, Japan Institute of Sports Sciences, Kita-ku, Japan
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26
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KIM DH, BAE GT, LEE JY. A novel vest with dual functions for firefighters: combined effects of body cooling and cold fluid ingestion on the alleviation of heat strain. INDUSTRIAL HEALTH 2020; 58:91-106. [PMID: 31257232 PMCID: PMC7118065 DOI: 10.2486/indhealth.2018-0205] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 06/25/2019] [Indexed: 06/09/2023]
Abstract
This study investigated the separate and combined effects of skin cooling and cold fluid ingestion on the alleviation of heat strain when wearing protective firefighting clothing at an air temperature of 30°C with 50%RH. A vest with the dual functions of cooling and providing sports drink supply (1.2% body mass) was developed. Eight males participated in the following four conditions: control [CON], drinking only [DO], cooling only [CO], and both cooling and drinking [CD]. The results showed that rectal (Tre), mean skin temperature (Tsk) and heart rate (HR) during recovery were lower for CD than for CON (p<0.05), while no significant differences between the four conditions were found during exercise. CO significantly reduced mean Tsk and HR and improved thermal sensation, whereas DO was effective for relieving thirst and lowering HR in recovery. In summary, the combined effect of skin cooling and fluid ingestion was synergistically manifested in Tre, Tsk and thermal sensation in recovery.Practitioner Summary: The present results provide data on a novel vest that contributes to alleviating firefighters' heat strain. Because a cooling vest after melting may be a burden for firefighters, this study indicates a practical way to reduce the additional weight load of the vest by drinking the melted fluid of the cooling packs.
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Affiliation(s)
- Do-Hyung KIM
- Department of Textiles, Merchandising and Fashion Design,
Seoul National University, Korea
| | - Gyu-Tae BAE
- Department of Textiles, Merchandising and Fashion Design,
Seoul National University, Korea
| | - Joo-Young LEE
- Department of Textiles, Merchandising and Fashion Design,
Seoul National University, Korea
- Research Institute for Human Ecology, Seoul National
University, Korea
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27
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Douzi W, Dupuy O, Theurot D, Smolander J, Dugué B. Per-Cooling (Using Cooling Systems during Physical Exercise) Enhances Physical and Cognitive Performances in Hot Environments. A Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E1031. [PMID: 32041228 PMCID: PMC7036802 DOI: 10.3390/ijerph17031031] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/25/2020] [Accepted: 01/29/2020] [Indexed: 12/19/2022]
Abstract
There are many important sport events that are organized in environments with a very hot ambient temperature (Summer Olympics, FIFA World Cup, Tour de France, etc.) and in hot locations (e.g., Qatar). Additionally, in the context of global warming and heat wave periods, athletes are often subjected to hot ambient temperatures. It is known that exercising in the heat induces disturbances that may provoke premature fatigue and negatively affects overall performance in both endurance and high intensity exercises. Deterioration in several cognitive functions may also occur, and individuals may be at risk for heat illnesses. To train, perform, work and recover and in a safe and effective way, cooling strategies have been proposed and have been routinely applied before, during and after exercise. However, there is a limited understanding of the influences of per-cooling on performance, and it is the subject of the present review. This work examines the influences of per-cooling of different areas of the body on performance in terms of intense short-term exercises ("anaerobic" exercises), endurance exercises ("aerobic" exercises), and cognitive functioning and provides detailed strategies that can be applied when individuals train and/or perform in high ambient temperatures.
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Affiliation(s)
| | | | | | | | - Benoit Dugué
- University of Poitiers, Laboratoire Mobilité Vieillissement Exercice (MOVE)-EA6314, Faculty of Sport Sciences, 8 Allée Jean Monnet, 86000 Poitiers, France; (W.D.); (O.D.); (D.T.); (J.S.)
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28
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Ad libitum water consumption off-sets the thermal and cardiovascular strain exacerbated by dehydration during a 3-h simulated heatwave. Eur J Appl Physiol 2019; 120:391-399. [DOI: 10.1007/s00421-019-04283-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/02/2019] [Indexed: 12/14/2022]
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29
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Gibson OR, James CA, Mee JA, Willmott AG, Turner G, Hayes M, Maxwell NS. Heat alleviation strategies for athletic performance: A review and practitioner guidelines. Temperature (Austin) 2019; 7:3-36. [PMID: 32166103 PMCID: PMC7053966 DOI: 10.1080/23328940.2019.1666624] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/06/2019] [Accepted: 09/08/2019] [Indexed: 12/19/2022] Open
Abstract
International competition inevitably presents logistical challenges for athletes. Events such as the Tokyo 2020 Olympic Games require further consideration given historical climate data suggest athletes will experience significant heat stress. Given the expected climate, athletes face major challenges to health and performance. With this in mind, heat alleviation strategies should be a fundamental consideration. This review provides a focused perspective of the relevant literature describing how practitioners can structure male and female athlete preparations for performance in hot, humid conditions. Whilst scientific literature commonly describes experimental work, with a primary focus on maximizing magnitudes of adaptive responses, this may sacrifice ecological validity, particularly for athletes whom must balance logistical considerations aligned with integrating environmental preparation around training, tapering and travel plans. Additionally, opportunities for sophisticated interventions may not be possible in the constrained environment of the athlete village or event arenas. This review therefore takes knowledge gained from robust experimental work, interprets it and provides direction on how practitioners/coaches can optimize their athletes' heat alleviation strategies. This review identifies two distinct heat alleviation themes that should be considered to form an individualized strategy for the athlete to enhance thermoregulatory/performance physiology. First, chronic heat alleviation techniques are outlined, these describe interventions such as heat acclimation, which are implemented pre, during and post-training to prepare for the increased heat stress. Second, acute heat alleviation techniques that are implemented immediately prior to, and sometimes during the event are discussed. Abbreviations: CWI: Cold water immersion; HA: Heat acclimation; HR: Heart rate; HSP: Heat shock protein; HWI: Hot water immersion; LTHA: Long-term heat acclimation; MTHA: Medium-term heat acclimation; ODHA: Once-daily heat acclimation; RH: Relative humidity; RPE: Rating of perceived exertion; STHA: Short-term heat acclimation; TCORE: Core temperature; TDHA: Twice-daily heat acclimation; TS: Thermal sensation; TSKIN: Skin temperature; V̇O2max: Maximal oxygen uptake; WGBT: Wet bulb globe temperature.
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Affiliation(s)
- Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, UK
| | - Carl A. James
- Institut Sukan Negara (National Sports Institute), Kuala Lumpur, Malaysia
| | - Jessica A. Mee
- School of Sport and Exercise Sciences, University of Worcester, Worcester, UK
| | - Ashley G.B. Willmott
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
| | - Gareth Turner
- Bisham Abbey National High-Performance Centre, English Institute of Sport, EIS Performance Centre, Marlow, UK
| | - Mark Hayes
- Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
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Vargas NT, Chapman CL, Johnson BD, Gathercole R, Cramer MN, Schlader ZJ. Thermal behavior alleviates thermal discomfort during steady-state exercise without affecting whole body heat loss. J Appl Physiol (1985) 2019; 127:984-994. [PMID: 31414951 DOI: 10.1152/japplphysiol.00379.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We tested the hypothesis that thermal behavior resulting in reductions in mean skin temperature alleviates thermal discomfort and mitigates the rise in core temperature during light-intensity exercise. In a 27 ± 0°C, 48 ± 6% relative humidity environment, 12 healthy subjects (6 men, 6 women) completed 60 min of recumbent cycling. In both trials, subjects wore a water-perfused suit top continually perfusing 34 ± 0°C water. In the behavior trial, subjects maintained their upper body thermally comfortable by pressing a button to perfuse cool water (2.2 ± 0.5°C) through the top for 2 min per button press. Metabolic heat production (control: 404 ± 52 W, behavior: 397 ± 65 W; P = 0.44) was similar between trials. Mean skin temperature was reduced in the behavior trial (by -2.1 ± 1.8°C, P < 0.01) because of voluntary reductions in water-perfused top temperature (P < 0.01). Whole body (P = 0.02) and local sweat rates were lower in the behavior trial (P ≤ 0.05). Absolute core temperature was similar (P ≥ 0.30); however, the change in core temperature was greater in the behavior trial after 40 min of exercise (P ≤ 0.03). Partitional calorimetry did not reveal any differences in cumulative heat storage (control: 554 ± 229, behavior: 544 ± 283 kJ; P = 0.90). Thermal behavior alleviated whole body thermal discomfort during exercise (by -1.17 ± 0.40 arbitrary units, P < 0.01). Despite lower evaporative cooling in the behavior trial, similar heat loss was achieved by voluntarily employing convective cooling. Therefore, thermal behavior resulting in large reductions in skin temperature is effective at alleviating thermal discomfort during exercise without affecting whole body heat loss.NEW & NOTEWORTHY This study aimed to determine the effectiveness of thermal behavior in maintaining thermal comfort during exercise by allowing subjects to voluntarily cool their torso and upper limbs with 2°C water throughout a light-intensity exercise protocol. We show that voluntary cooling of the upper body alleviates thermal discomfort while maintaining heat balance through convective rather than evaporative means of heat loss.
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Affiliation(s)
- Nicole T Vargas
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Christopher L Chapman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Blair D Johnson
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Rob Gathercole
- lululemon athletica inc., Vancouver, British Columbia, Canada
| | - Matthew N Cramer
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
| | - Zachary J Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York.,Department of Kinesiology, School of Public Health, Indiana University, Bloomington, Indiana
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Racinais S, Casa D, Brocherie F, Ihsan M. Translating Science Into Practice: The Perspective of the Doha 2019 IAAF World Championships in the Heat. Front Sports Act Living 2019; 1:39. [PMID: 33344962 PMCID: PMC7739640 DOI: 10.3389/fspor.2019.00039] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 09/16/2019] [Indexed: 01/26/2023] Open
Abstract
Hot and humid ambient conditions may play a major role during the endurance events of the 2019 IAAF world championships, the 2020 summer Olympics and many other sports events. Here, various countermeasures with scientific evidence are put in perspective of their practical application. This manuscript is not a comprehensive review, but rather a set of applied recommendations built upon sound scientific reasoning and experience with elite athletes. The primary recommendation for an athlete who will be competing in the heat, will be to train in the heat. This acclimatization phase should last for 2 weeks and be programmed to accommodate the taper and travel requirements. Despite extensive laboratory-based research, hydration strategies within athletics are generally dictated by the race characteristics. The main opportunities for hydration are during the preparation and recovery phases. In competition, depending on thirst, feeling, and energy requirements, water may be ingested or poured. The athletes should also adapt their warm-up routines to the environmental conditions, as it may do more harm than good. Avoiding harm includes limiting unnecessary heat exposure before the event, warming-up with cooling aids such as ice-vest or cold/iced drinks, and avoiding clothing or accessories limiting sweat evaporation. From a medical perspective, exertional heat stroke should be considered immediately when an athlete collapses or struggles during exercise in the heat with central nervous system disorders. Once a rectal temperature >40.5°C is confirmed, cooling (via cold water immersion) should be undertaken as soon as possible (cool first/transport second).
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Affiliation(s)
| | - Douglas Casa
- Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT, United States
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance, French Institute of Sport (INSEP), Paris, France
| | - Mohammed Ihsan
- Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
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Griggs KE, Stephenson BT, Price MJ, Goosey-Tolfrey VL. Heat-related issues and practical applications for Paralympic athletes at Tokyo 2020. Temperature (Austin) 2019; 7:37-57. [PMID: 32166104 PMCID: PMC7053936 DOI: 10.1080/23328940.2019.1617030] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 02/07/2023] Open
Abstract
International sporting competitions, including the Paralympic Games, are increasingly being held in hot and/or humid environmental conditions. Thus, a greater emphasis is being placed on preparing athletes for the potentially challenging environmental conditions of the host cities, such as the upcoming Games in Tokyo in 2020. However, evidence-based practices are limited for the impairment groups that are eligible to compete in Paralympic sport. This review aims to provide an overview of heat-related issues for Paralympic athletes alongside current recommendations to reduce thermal strain and technological advancements in the lead up to the Tokyo 2020 Paralympic Games. When competing in challenging environmental conditions, a number of factors may contribute to an athlete's predisposition to heightened thermal strain. These include the characteristics of the sport itself (type, intensity, duration, modality, and environmental conditions), the complexity and severity of the impairment and classification of the athlete. For heat vulnerable Paralympic athletes, strategies such as the implementation of cooling methods and heat acclimation can be used to combat the increase in heat strain. At an organizational level, regulations and specific heat policies should be considered for several Paralympic sports. Both the utilization of individual strategies and specific heat health policies should be employed to ensure that Paralympics athletes' health and sporting performance are not negatively affected during the competition in the heat at the Tokyo 2020 Paralympic Games.
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Affiliation(s)
- Katy E. Griggs
- Department of Engineering, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Ben T. Stephenson
- Loughborough Performance Centre, English Institute of Sport, Loughborough University, Loughborough, UK
- Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Michael J. Price
- School of Life Sciences, Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, UK
| | - Victoria L. Goosey-Tolfrey
- Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
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Costa RJS, Gaskell SK, McCubbin AJ, Snipe RMJ. Exertional-heat stress-associated gastrointestinal perturbations during Olympic sports: Management strategies for athletes preparing and competing in the 2020 Tokyo Olympic Games. Temperature (Austin) 2019; 7:58-88. [PMID: 32166105 PMCID: PMC7053925 DOI: 10.1080/23328940.2019.1597676] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/05/2019] [Accepted: 03/14/2019] [Indexed: 12/15/2022] Open
Abstract
Exercise-induced gastrointestinal syndrome (EIGS) is a common characteristic of exercise. The causes appear to be multifactorial in origin, but stem primarily from splanchnic hypoperfusion and increased sympathetic drive. These primary causes can lead to secondary outcomes that include increased intestinal epithelial injury and gastrointestinal hyperpermeability, systemic endotoxemia, and responsive cytokinemia, and impaired gastrointestinal function (i.e. transit, digestion, and absorption). Impaired gastrointestinal integrity and functional responses may predispose individuals, engaged in strenuous exercise, to gastrointestinal symptoms (GIS), and health complications of clinical significance, both of which may have exercise performance implications. There is a growing body of evidence indicating heat exposure during exercise (i.e. exertional-heat stress) can substantially exacerbate these gastrointestinal perturbations, proportionally to the magnitude of exertional-heat stress, which is of major concern for athletes preparing for and competing in the upcoming 2020 Tokyo Olympic Games. To date, various hydration and nutritional strategies have been explored to prevent or ameliorate exertional-heat stress associated gastrointestinal perturbations. The aims of the current review are to comprehensively explore the impact of exertional-heat stress on markers of EIGS, examine the evidence for the prevention and (or) management of EIGS in relation to exertional-heat stress, and establish best-practice nutritional recommendations for counteracting EIGS and associated GIS in athletes preparing for and competing in Tokyo 2020.
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Affiliation(s)
- Ricardo J S Costa
- Monash University, Department of Nutrition Dietetics and Food, Notting Hill, Victoria, Australia
| | - Stephanie K Gaskell
- Monash University, Department of Nutrition Dietetics and Food, Notting Hill, Victoria, Australia
| | - Alan J McCubbin
- Monash University, Department of Nutrition Dietetics and Food, Notting Hill, Victoria, Australia
| | - Rhiannon M J Snipe
- Deakin University, Centre for Sport Research, School of Exercise and Nutrition Science, Burwood, Victoria, Australia
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FORSYTH PETA, MILLER JOANNA, PUMPA KATE, THOMPSON KEVING, JAY OLLIE. Independent Influence of Spinal Cord Injury Level on Thermoregulation during Exercise. Med Sci Sports Exerc 2019; 51:1710-1719. [DOI: 10.1249/mss.0000000000001978] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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NG JASON, DOBBS WARDC, WINGO JONATHANE. Effect of Ice Slurry Ingestion on Cardiovascular Drift and V˙O2max during Heat Stress. Med Sci Sports Exerc 2019; 51:582-589. [DOI: 10.1249/mss.0000000000001794] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Choo HC, Peiffer JJ, Lopes-Silva JP, Mesquita RNO, Amano T, Kondo N, Abbiss CR. Effect of ice slushy ingestion and cold water immersion on thermoregulatory behavior. PLoS One 2019; 14:e0212966. [PMID: 30811512 PMCID: PMC6392407 DOI: 10.1371/journal.pone.0212966] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 02/12/2019] [Indexed: 11/18/2022] Open
Abstract
Two studies were conducted to examine the effects of ice slushy ingestion (ICE) and cold water immersion (CWI) on thermoregulatory and sweat responses during constant (study 1) and self-paced (study 2) exercise. In study 1, 11 men cycled at 40-50% of peak aerobic power for 60 min (33.2 ± 0.3°C, 45.9 ± 0.5% relative humidity, RH). In study 2, 11 men cycled for 60 min at perceived exertion (RPE) equivalent to 15 (33.9 ± 0.2°C and 42.5 ± 3.9%RH). In both studies, each trial was preceded by 30 min of CWI (~22°C), ICE or no cooling (CON). Rectal temperature (Tre), skin temperature (Tsk), thermal sensation, and sweat responses were measured. In study 1, ICE decreased Tre-Tsk gradient versus CON (p = 0.005) during first 5 min of exercise, while CWI increased Tre-Tsk gradient versus CON and ICE for up to 20 min during the exercise (p<0.05). In study 2, thermal sensation was lower in CWI versus CON and ICE for up to 35-40 min during the exercise (p<0.05). ICE reduced thermal sensation versus CON during the first 20 min of exercise (p<0.05). In study 2, CWI improved mean power output (MPO) by ~8 W, compared with CON only (p = 0.024). In both studies, CWI (p<0.001) and ICE (p = 0.019) delayed sweating by 1-5 min but did not change the body temperature sweating threshold, compared with CON (both p>0.05). Increased Tre-Tsk gradient by CWI improved MPO while ICE reduced Tre but did not confer any ergogenic effect. Both precooling treatments attenuated the thermal efferent signals until a specific body temperature threshold was reached.
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Affiliation(s)
- Hui C. Choo
- Centre for Exercise and Sports Science Research, School of Medical and
Health Sciences, Edith Cowan University, Joondalup, Western Australia,
Australia
- * E-mail:
| | - Jeremiah J. Peiffer
- School of Psychology and Exercise Science, Murdoch University, Murdoch,
Western, Australia, Australia
| | - João P. Lopes-Silva
- School of Physical Education and Sport, University of São Paulo (USP),
São Paulo, São Paulo, Brazil
| | - Ricardo N. O. Mesquita
- Centre for Exercise and Sports Science Research, School of Medical and
Health Sciences, Edith Cowan University, Joondalup, Western Australia,
Australia
| | - Tatsuro Amano
- Faculty of Education, Niigata University, Niigata, Niigata Prefecture,
Japan
| | - Narihiko Kondo
- Laboratory for Applied Human Physiology, Graduate School of Human
Development and Environment, Kobe University, Kobe, Hyōgo Prefecture,
Japan
| | - Chris R. Abbiss
- Centre for Exercise and Sports Science Research, School of Medical and
Health Sciences, Edith Cowan University, Joondalup, Western Australia,
Australia
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Cramer MN, Jay O. Partitional calorimetry. J Appl Physiol (1985) 2019; 126:267-277. [PMID: 30496710 PMCID: PMC6397408 DOI: 10.1152/japplphysiol.00191.2018] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 11/19/2018] [Accepted: 11/26/2018] [Indexed: 11/22/2022] Open
Abstract
For thermal physiologists, calorimetry is an important methodological tool to assess human heat balance during heat or cold exposures. A whole body direct calorimeter remains the gold standard instrument for assessing human heat balance; however, this equipment is rarely available to most researchers. A more widely accessible substitute is partitional calorimetry, a method by which all components of the conceptual heat balance equation-metabolic heat production, conduction, radiation, convection, and evaporation-are calculated separately based on fundamental properties of energy exchange. Since partitional calorimetry requires relatively inexpensive equipment (vs. direct calorimetry) and can be used over a wider range of experimental conditions (i.e., different physical activities, laboratory or field settings, clothed or seminude), it allows investigators to address a wide range of problems such as predicting human responses to thermal stress, developing climatic exposure limits and fluid replacement guidelines, estimating clothing properties, evaluating cooling/warming interventions, and identifying potential thermoregulatory dysfunction in unique populations. In this Cores of Reproducibility in Physiology (CORP) review, we summarize the fundamental principles underlying the use of partitional calorimetry, present the various methodological and arithmetic requirements, and provide typical examples of its use. Strategies to minimize estimation error of specific heat balance components, as well as the limitations of the method, are also discussed. The goal of this CORP paper is to present a standardized methodology and thus improve the accuracy and reproducibility of research employing partitional calorimetry.
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Affiliation(s)
- Matthew N Cramer
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center , Dallas, Texas
| | - Ollie Jay
- Thermal Ergonomics Laboratory, Faculty of Health Sciences, The University of Sydney , Sydney, NSW , Australia
- Charles Perkins Centre, The University of Sydney , Sydney, NSW , Australia
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Naito T, Sagayama H, Akazawa N, Haramura M, Tasaki M, Takahashi H. Ice slurry ingestion during break times attenuates the increase of core temperature in a simulation of physical demand of match-play tennis in the heat. Temperature (Austin) 2018; 5:371-379. [PMID: 30574529 DOI: 10.1080/23328940.2018.1475989] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/09/2018] [Indexed: 10/28/2022] Open
Abstract
This investigation assessed the effect of ice slurry ingestion compared to that of cold water ingestion during break times on thermal strain and perception in simulated match-play tennis in the heat. Seven male recreational athletes (age = 22 ± 2 yr, height = 1.72 ± 0.08 m, Body mass = 64.8 ± 6.8 kg) performed two trials in a climate chamber, each time completing 4 sets of simulated match-play. During International Tennis Federation-mandated breaks (90-s between odd-numbered games; 120-s between sets), either ice slurry or cold water were ingested. The rectal temperature, forehead skin temperature, heart rate, rating of thermal comfort and total sweat loss were measured. The change in rectal temperature in the ice slurry trial was significantly lower than that in the cold water trial by game 3 of set 3 (p = 0.02). These differences in Δrectal temperature persisted throughout the remainder of the "match" (p < 0.05). Forehead skin temperature, heart rate and rating of thermal comfort were significantly lower in the ice slurry trial than in the cold water trial by the second half of the experiment (p < 0.05). Total sweat loss in ice slurry trial is significantly lower than cold water trial (p = 0.002). These results suggested that ice slurry ingestion was more effective than cold water ingestion in mitigating the development of heat strain during simulated match-play tennis in the heat.
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Affiliation(s)
| | - Hiroyuki Sagayama
- Japan Institute of Sport Sciences, Tokyo, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | | | | | - Masahiro Tasaki
- Japan Institute of Sport Sciences, Tokyo, Japan.,Saitama Prefectural Kasukabe Higashi High School, Saitama, Japan
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39
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Abstract
Cold water or ice slurry ingestion during exercise seems to be an effective and practical means to improve endurance exercise performance in the heat. However, transient reductions in sweating appear to decrease the potential for evaporative heat loss from the skin by a magnitude that at least negates the additional internal heat loss as a cold ingested fluid warms up to equilibrate with body temperature; thus explaining equivalent core temperatures during exercise at a fixed heat production irrespective of the ingested fluid temperature. Internal heat transfer with cold fluid/ice is always 100% efficient; therefore, when a decrement occurs in the efficiency that sweat evaporates from the skin surface (i.e. sweating efficiency), a net cooling effect should begin to develop. Using established relationships between activity, climate and sweating efficiency, the boundary conditions beyond which cold ingested fluids are beneficial in terms of increasing net heat loss can be calculated. These conditions are warmer and more humid for cycling relative to running by virtue of the greater skin surface airflow, which promotes evaporation, for a given metabolic heat production and thus sweat rate. Within these boundary conditions, athletes should ingest fluids at the temperature they find most palatable, which likely varies from athlete to athlete, and therefore best maintain hydration status. The cooling benefits of cold fluid/ice ingestion during exercise are likely disproportionately greater for athletes with physiological disruptions to sweating, such as those with a spinal cord injury or burn injuries, as their capacity for skin surface evaporative heat loss is much lower; however, more research examining these groups is needed.
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Morris NB, Chaseling GK, Bain AR, Jay O. Temperature of water ingested before exercise alters the onset of physiological heat loss responses. Am J Physiol Regul Integr Comp Physiol 2018; 316:R13-R20. [PMID: 30403496 DOI: 10.1152/ajpregu.00028.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study sought to determine whether the temperature of water ingested before exercise alters the onset threshold and subsequent thermosensitivity of local vasomotor and sudomotor responses after exercise begins. Twenty men [24 (SD 4) yr of age, 75.8 (SD 8.1) kg body mass, 52.3 (SD 7.7) ml·min-1·kg-1 peak O2 consumption (V̇o2peak)] ingested 1.5°C, 37°C, or 50°C water (3.2 ml/kg), rested for 5 min, and then cycled at 50% V̇o2peak for 15 min at 23.0 (SD 0.9) °C and 32 (SD 10) % relative humidity. Mean body temperature (Tb), local sweat rate (LSR), and skin blood flow (SBF) were measured. In a subset of eight men [25 (SD 5) yr of age, 78.6 (SD 8.3) kg body mass, 48.9 (SD 11.1) ml·min-1·kg-1 V̇o2peak], blood pressure was measured and cutaneous vascular conductance (CVC) was determined. The change in Tb was greater at the onset of LSR measurement with ingestion of 1.5°C than 50°C water [ΔTb = 0.19 (SD 0.15) vs. 0.11 (SD 0.12) °C, P = 0.04], but not 37°C water [ΔTb = 0.14 (SD 0.14) °C, P = 0.23], but did not differ between trials for SBF measurement [ΔTb = 0.18 (SD 0.15) °C, 0.11 (SD 0.13) °C, and 0.09 (SD 0.09) °C with 1.5°C, 37°C, and 50°C water, respectively, P = 0.07]. Conversely, the thermosensitivity of LSR and SBF was not different [LSR = 1.11 (SD 0.75), 1.11 (SD 0.75), and 1.34 (SD 1.11) mg·min-1·cm-2·°C-1 with 1.5°C, 37°C, and 50°C ingested water, respectively ( P = 0.46); SBF = 717 (SD 882), 517 (SD 606), and 857 (SD 904) %baseline arbitrary units (AU)/°C with 1.5°C, 37°C, and 50°C ingested water, respectively ( P = 0.95)]. After 15 min of exercise, LSR and SBF were greater with ingestion of 50°C than 1.5°C water [LSR = 0.40 (SD 0.17) vs. 0.31 (SD 0.19) mg·min-1·cm-2 ( P = 0.02); SBF = 407 (SD 149) vs. 279 (SD 117) %baseline AU ( P < 0.001)], but not 37°C water [LSR = 0.50 (SD 0.22) mg·min-1·cm-2; SBF = 324 (SD 169) %baseline AU]. CVC was statistically unaffected [275 (SD 81), 340 (SD 114), and 384 (SD 160) %baseline CVC with 1.5°C, 37°C, and 50°C ingested water, respectively, P = 0.30]. Collectively, these results support the concept that visceral thermoreceptors modify the central drive for thermoeffector responses.
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Affiliation(s)
- Nathan B Morris
- Thermal Ergonomics Laboratory, Exercise and Sport Science, Faculty of Health Sciences, University of Sydney , Sydney, New South Wales , Australia.,School of Human Kinetics, University of Ottawa , Ottawa, Ontario , Canada
| | - Georgia K Chaseling
- Thermal Ergonomics Laboratory, Exercise and Sport Science, Faculty of Health Sciences, University of Sydney , Sydney, New South Wales , Australia
| | - Anthony R Bain
- School of Human Kinetics, University of Ottawa , Ottawa, Ontario , Canada.,Integrative Vascular Biology Laboratory, Department of Integrative Physiology, University of Colorado , Boulder, Colorado
| | - Ollie Jay
- Thermal Ergonomics Laboratory, Exercise and Sport Science, Faculty of Health Sciences, University of Sydney , Sydney, New South Wales , Australia.,School of Human Kinetics, University of Ottawa , Ottawa, Ontario , Canada
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Sarafian D, Maufrais C, Montani JP. Early and Late Cardiovascular and Metabolic Responses to Mixed Wine: Effect of Drink Temperature. Front Physiol 2018; 9:1334. [PMID: 30319445 PMCID: PMC6168674 DOI: 10.3389/fphys.2018.01334] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/04/2018] [Indexed: 12/17/2022] Open
Abstract
Aim: Red wine is usually ingested as an unmixed drink. However, mixtures of wine with juices and/or sucrose (mixed wine) are becoming more and more popular and could be ingested at either cold or hot temperature. Although the temperature effects on the cardiovascular system have been described for water and tea, with greater energy expenditure (EE) and lower cardiac workload with a colder drink, little information is available on the impact of temperature of alcoholic beverages on alcoholemia and cardiometabolic parameters. The purpose of the present study was to compare the acute cardiovascular and metabolic changes in response to mixed wine ingested at a cold or at a hot temperature. Methods: In a randomized crossover design, 14 healthy young adults (seven men and seven women) were assigned to cold or hot mixed wine ingestion. Continuous cardiovascular, metabolic, and cutaneous monitoring was performed in a comfortable sitting position during a 30-min baseline and for 120 min after ingesting 400 ml of mixed wine, with the alcohol content adjusted to provide 0.4 g ethanol/kg of body weight and drunk at either cold (3°C) or hot (55°C) temperature. Breath alcohol concentration was measured intermittently throughout the study. Results: Overall, alcoholemia was not altered by drink temperature, with a tendency toward greater values in women compared to men. Early responses to mixed wine ingestion (0–20 min) indicated that cold drink transiently increased mean blood pressure (BP), cardiac vagal tone, and decreased skin blood flow (SkBf) whereas hot drink did not change BP, decreased vagal tone, and increased SkBf. Both cold and hot mixed wine led to increases in EE and reductions in respiratory quotient. Late responses (60–120 min) led to similar cardiovascular and metabolic changes at both drink temperatures. Conclusion: The magnitude and/or the directional change of most of the study variables differed during the first 20 min following ingestion and may be related to drink temperature. By contrast, late changes in cardiometabolic outcomes were similar between cold and hot wine ingestion, underlying the typical effect of alcohol and sugar intake on the cardiovascular system.
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Affiliation(s)
- Delphine Sarafian
- Laboratory of Integrative Cardiovascular and Metabolic Physiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Claire Maufrais
- Laboratory of Integrative Cardiovascular and Metabolic Physiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Jean-Pierre Montani
- Laboratory of Integrative Cardiovascular and Metabolic Physiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
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Does the temperature of water ingested during exertional-heat stress influence gastrointestinal injury, symptoms, and systemic inflammatory profile? J Sci Med Sport 2018; 21:771-776. [DOI: 10.1016/j.jsams.2017.12.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 12/10/2017] [Accepted: 12/29/2017] [Indexed: 11/23/2022]
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Watkins ER, Hayes M, Watt P, Richardson AJ. Practical pre-cooling methods for occupational heat exposure. APPLIED ERGONOMICS 2018; 70:26-33. [PMID: 29866317 DOI: 10.1016/j.apergo.2018.01.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 01/12/2018] [Accepted: 01/27/2018] [Indexed: 05/04/2023]
Abstract
This study aimed to identify a pre-cooling method to reduce the physiological and perceptual strain, and the inflammatory response, experienced by individuals who wear personal protective equipment. Eleven males (age 20 ± 2 years, weight 75.8 ± 9.3 kg, height 177.1 ± 5.0 cm) completed 15min pre-cooling (phase change vest [PCV], forearm cooling [ARM], ice slurry consumption [ICE], or a no cooling control [CON]) and 45min intermittent walk (4 km h-1, 1% gradient) in 49.5 ± 0.6 °C and 15.4 ± 1.0% RH, whilst wearing firefighter ensemble. ICE reduced rectal temperature (Tre) before heat exposure compared to CON (ΔTre: 0.24 ± 0.09 °C, p < 0.001, d = 0.38) and during exercise compared to CON, ARM, and PCV (p = 0.026, ηp2 = 0.145). Thermal sensation was reduced in ICE and ARM vs. CON (p = 0.018, ηp2 = 0.150). Interleukin-6 was not affected by pre-cooling (p = 0.648, ηp2 = 0.032). It is recommended that those wearing protective equipment consume 500 ml of ice slurry 15min prior to work to reduce physiological and perceptual strain.
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Affiliation(s)
- Emily R Watkins
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Eastbourne, UK.
| | - Mark Hayes
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Eastbourne, UK
| | - Peter Watt
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Eastbourne, UK
| | - Alan J Richardson
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Eastbourne, UK
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Ruddock A, Robbins B, Tew G, Bourke L, Purvis A. Practical Cooling Strategies During Continuous Exercise in Hot Environments: A Systematic Review and Meta-Analysis. Sports Med 2018; 47:517-532. [PMID: 27480762 PMCID: PMC5309298 DOI: 10.1007/s40279-016-0592-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Background Performing exercise in thermally stressful environments impairs exercise capacity and performance. Cooling during exercise has the potential to attenuate detrimental increases in body temperature and improve exercise capacity and performance. Objective The objective of this review was to assess the effectiveness of practical cooling strategies applied during continuous exercise in hot environments on body temperature, heart rate, whole body sweat production, rating of perceived exertion (RPE), thermal perception and exercise performance. Methods Electronic database searches of MEDLINE, SPORTDiscus, Scopus and Physiotherapy Evidence Database (PEDro) were conducted using medical subject headings, indexing terms and keywords. Studies were eligible if participants were defined as ‘healthy’, the exercise task was conducted in an environment ≥25 °C, it used a cooling strategy that would be practical for athletes to use during competition, cooling was applied during a self-paced or fixed-intensity trial, participants exercised continuously, and the study was a randomised controlled trial with the comparator either a thermoneutral equivalent or no cooling. Data for experimental and comparator groups were meta-analysed and expressed as a standardised mean difference and 95 % confidence interval. Results Fourteen studies including 135 participants met the eligibility criteria. Confidence intervals for meta-analysed data included beneficial and detrimental effects for cooling during exercise on core temperature, mean skin temperature, heart rate and sweat production during fixed-intensity exercise. Cooling benefited RPE and thermal perception during fixed-intensity exercise and improved self-paced exercise performance. Conclusion Cooling during fixed-intensity exercise, particularly before a self-paced exercise trial, improves endurance performance in hot environments by benefiting RPE and thermal perception, but does not appear to attenuate increases in body temperature.
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Affiliation(s)
- Alan Ruddock
- Centre for Sport and Exercise Science, Sheffield Hallam University, A016 Collegiate Hall, Sheffield, S10 2BP, UK.
| | - Brent Robbins
- Centre for Sport and Exercise Science, Sheffield Hallam University, A016 Collegiate Hall, Sheffield, S10 2BP, UK
| | - Garry Tew
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Room 244 Northumberland Building, Newcastle upon Tyne, NE1 8ST, UK
| | - Liam Bourke
- Centre for Sport and Exercise Science, Sheffield Hallam University, A121 Collegiate Hall, Sheffield, S10 2BP, UK
| | - Alison Purvis
- Faculty of Health and Wellbeing, Sheffield Hallam University, F616 Robert Winston Building, Sheffield, S10 2BP, UK
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CHASELING GEORGIAK, FILINGERI DAVIDE, BARNETT MICHAEL, HOANG PHU, DAVIS SCOTTL, JAY OLLIE. Cold Water Ingestion Improves Exercise Tolerance of Heat-Sensitive People with MS. Med Sci Sports Exerc 2018; 50:643-648. [DOI: 10.1249/mss.0000000000001496] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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46
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Mejuto G, Chalmers S, Gilbert S, Bentley D. The effect of ice slurry ingestion on body temperature and cycling performance in competitive athletes. J Therm Biol 2018; 72:143-147. [PMID: 29496007 DOI: 10.1016/j.jtherbio.2018.01.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 01/17/2018] [Accepted: 01/31/2018] [Indexed: 10/18/2022]
Abstract
The effects of pre cooling on endurance performance are widely known. In contrast, the approach of cooling during endurance exercise in combination with pre-exercise cooling has been poorly understood. The purpose of the present study was to determine whether the effects of precooling and cooling during exercise enhance exercise performance compared to the ingestion of a thermo-neutral beverage (20 °C) or precooling alone in cycling performance. This was an experimental study using a randomised crossover design in which 7 cyclists underwent three trials comprising of 45 min steady state cycling (SS) at 70% VO2 max and a subsequent 10 km time trial (TT) in hot conditions (32 °C, 50% relative humidity). Rectal temperature (Tre), heat storage (HS), heart rate (HR), blood lactate concentration (BLA) and thermal sensation (TS) were measured. The intervention consisted of: (1) ingestion of thermo-neutral beverage before and during SS cycling (TN), (2) ingestion of ice slurry beverage and application of iced towels (precooling) prior to exercise, and then ingestion of thermo-neutral beverage during SS (PRE) and (3) precooling strategy as above plus ice slurry ingestion during SS cycling (PRE + MID). The intake of thermo-neutral or ice slurry beverage (14 g/kg) occurred over 30 min before and every 15 min during SS cycling. There was no significant difference in TT performance between all the conditions (P =0.72). However, PRE and PRE + MID caused a significant decrease in Tre (P < 0.05) from TN during exercise. Accordingly, both precooling and a combination of precooling and mid-cooling during exercise in hot conditions may be a practical and effective way of reducing core temperature. Future studies should investigate longer distance events and timing of ice slurry ingestion.
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Affiliation(s)
| | - Samuel Chalmers
- Western Sydney University, School of Science and Health, NSW, Australia; University of South Australia, Division of Health Sciences, SA, Australia
| | | | - David Bentley
- Flinders University, Faculty of Medicine Nursing and Health Sciences, Adelaide, SA, Australia
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47
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Choo HC, Nosaka K, Peiffer JJ, Ihsan M, Abbiss CR. Ergogenic effects of precooling with cold water immersion and ice ingestion: A meta-analysis. Eur J Sport Sci 2017; 18:170-181. [DOI: 10.1080/17461391.2017.1405077] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Hui C. Choo
- Centre for Exercise and Sports Science Research (CESSR), School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA, Australia
| | - Kazunori Nosaka
- Centre for Exercise and Sports Science Research (CESSR), School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA, Australia
| | - Jeremiah J. Peiffer
- School of Psychology and Exercise Science, Murdoch University, 90 South St, Murdoch, WA, Australia
| | - Mohammed Ihsan
- Athlete Health and Performance Research Centre, ASPETAR – Qatar Orthopaedic and Sports Medicine Hospital, P.O. Box 29222, Doha, Qatar
| | - Chris R. Abbiss
- Centre for Exercise and Sports Science Research (CESSR), School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA, Australia
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Relf R, Willmott A, Mee J, Gibson O, Saunders A, Hayes M, Maxwell N. Females exposed to 24 h of sleep deprivation do not experience greater physiological strain, but do perceive heat illness symptoms more severely, during exercise-heat stress. J Sports Sci 2017; 36:348-355. [DOI: 10.1080/02640414.2017.1306652] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Rebecca Relf
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Ashley Willmott
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Jessica Mee
- School of Sport, Health and Exercise Sciences (SSHES), Bangor University, North Wales, UK
| | - Oliver Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, UK
| | - Arron Saunders
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Mark Hayes
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Neil Maxwell
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
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Butts CL, Smith CR, Ganio MS, McDermott BP. Physiological and perceptual effects of a cooling garment during simulated industrial work in the heat. APPLIED ERGONOMICS 2017; 59:442-448. [PMID: 27890156 DOI: 10.1016/j.apergo.2016.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 08/02/2016] [Accepted: 10/04/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE Evaluate physiological and perceptual responses using a phase change cooling (PCC) garment during simulated work in the heat. METHODS Twenty males wearing compression undergarments, coverall suit, gloves, and hard-hat, completed two randomly assigned trials (with PCC inserts or control, CON) of simulated industrial tasks in the heat (34.2 ± 0.05 °C, 54.7 ± 0.3%RH). Trials consisted of two 20 min work bouts, a maximum performance bout, and 10 min of recovery. RESULTS Physiological strain index (PSI) was lower during PCC after the second work bout and during recovery (all P < 0.05). PCC reduced heat storage (27.0 ± 7.6 W m-2) compared to CON (42.7 ± 9.9 W m-2, P < 0.001). Perceptual strain index (PeSI) was reduced with PCC compared to CON (P < 0.001), however performance outcomes were not different between trials (P = 0.10). CONCLUSIONS PCC during work in the heat attenuated thermal, physiological, and perceptual strain. This PCC garment could increase safety and reduce occupational heat illness risk.
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Affiliation(s)
- Cory L Butts
- Human Performance Laboratory, University of Arkansas, 155 Stadium Dr HPER 321, Fayetteville, AR 72701, USA.
| | - Cody R Smith
- Human Performance Laboratory, University of Arkansas, 155 Stadium Dr HPER 321, Fayetteville, AR 72701, USA.
| | - Matthew S Ganio
- Human Performance Laboratory, University of Arkansas, 155 Stadium Dr HPER 321, Fayetteville, AR 72701, USA.
| | - Brendon P McDermott
- Human Performance Laboratory, University of Arkansas, 155 Stadium Dr HPER 321, Fayetteville, AR 72701, USA.
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Takeshima K, Onitsuka S, Xinyan Z, Hasegawa H. Effect of the timing of ice slurry ingestion for precooling on endurance exercise capacity in a warm environment. J Therm Biol 2017; 65:26-31. [PMID: 28343572 DOI: 10.1016/j.jtherbio.2017.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 01/23/2017] [Accepted: 01/23/2017] [Indexed: 11/30/2022]
Abstract
It has been demonstrated that precooling with ice slurry ingestion enhances endurance exercise capacity in the heat. However, no studies have yet evaluated the optimal timing of ice slurry ingestion for precooling. This study aimed to investigate the effects of varying the timing of ice slurry ingestion for precooling on endurance exercise capacity in a warm environment. Ten active male participants completed 3 experimental cycling trials to exhaustion at 55% peak power output (PPO) after 15min of warm-up at 30% PPO at 30°C and 80% relative humidity. Three experimental conditions were set: no ice slurry ingestion (CON), pre-warm-up ice slurry ingestion (-1°C; 7.5gkg-1) (PRE), and post-warm-up ice slurry ingestion (POST). Rectal and mean skin temperatures at the beginning of exercise in the POST condition (37.1±0.2°C, 33.8±0.9°C, respectively) were lower than those in the CON (37.5±0.3°C; P<0.001, 34.8±0.8°C; P<0.01, respectively) and PRE (37.4±0.2°C; P<0.01, 34.6±0.7°C; P<0.01, respectively) conditions. These reductions increased heat storage capacity and resulted in improved exercise capacity in the POST condition (60.2±8.7min) compared to that in the CON (52.0±11.9min; effect size [ES]=0.78) and PRE (56.9±10.4min; ES=0.34) conditions. Ice slurry ingestion after warm-up effectively reduced both rectal and skin temperatures and increased cycling time to exhaustion in a warm environment. Timing ice slurry ingestion to occur after warm-up may be effective for precooling in a warm environment.
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Affiliation(s)
- Keisuke Takeshima
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Japan
| | - Sumire Onitsuka
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Japan
| | - Zheng Xinyan
- Department of Sport Science, Shanghai University of Sport, Shanghai, China
| | - Hiroshi Hasegawa
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Japan.
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