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Morito A, Inami T, Hirata A, Yamada S, Shimomasuda M, Haramoto M, Kato K, Tahara S, Oguma Y, Ishida H, Kohtake N. Ice slurry ingestion improves physical performance during high-intensity intermittent exercise in a hot environment. PLoS One 2022; 17:e0274584. [PMID: 36107972 PMCID: PMC9477354 DOI: 10.1371/journal.pone.0274584] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 08/30/2022] [Indexed: 12/03/2022] Open
Abstract
Ice slurry ingestion enhances exercise performance by lowering the core body temperature. However, an operational issue related to this ingestion is the requirement for a high intake of 7.5 g·kg-1 to produce the desired effects. We investigated the effects of the intake of low amounts of ice slurry at −2°C on the tympanic temperature and exercise performance during repeated high-intensity intermittent exercises in a hot environment. This study was a randomized, crossover study, with a 6-day washout period. Twelve university rugby union players performed two 30-min sessions of high-intensity intermittent exercises separated by a 15-min half-time break on a cycle ergometer in a hot environment (28.8°C ± 0.1°C, 49.5% ± 0.6% relative humidity). The participants ingested 450 g of −2°C-ice slurry (ICE), or a 30°C-beverage (CON) having the same composition as ICE, or 30°C-water (WAT) during the half-time break. The tympanic temperature and skin temperature were measured as the physiological data, and the peak power and mean power as the exercise performance data. The tympanic temperature at the half-time break and beginning of the 2nd session was significantly lower in the ICE group as compared with the CON and WAT groups. The skin temperature at the half-time break was significantly lower in the ICE group as compared with the WAT group. While the peak power and mean power during the 2nd session were significantly greater in the ICE group as compared with the CON and WAT groups. Our findings suggest that even the intake of lower amounts, as compared with those used in previous studies, of low-temperature ice slurry can reduce the body temperature and improve the peak power. These results suggest that intake of low-temperature ice slurry as a strategy for internal body cooling is useful for improving endurance exercise performance in hot environments.
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Affiliation(s)
- Akihisa Morito
- Graduate School of System Design and Management, Keio University, Kanagawa, Japan
- R&D Laboratories, Self-Medication, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
- * E-mail:
| | - Takayuki Inami
- Institute of Physical Education, Keio University, Kanagawa, Japan
| | - Akihiro Hirata
- Graduate School of System Design and Management, Keio University, Kanagawa, Japan
- Sports Medicine Research Center, Keio University, Kanagawa, Japan
| | - Satoshi Yamada
- R&D Laboratories, Self-Medication, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Masatsugu Shimomasuda
- Research & Development Headquarters, Self-Medication, Taisho Pharmaceutical Co., Ltd., Tokyo, Japan
| | - Maki Haramoto
- Research & Development Headquarters, Self-Medication, Taisho Pharmaceutical Co., Ltd., Tokyo, Japan
| | - Keita Kato
- R&D Laboratories, Self-Medication, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Shigeyuki Tahara
- Graduate School of System Design and Management, Keio University, Kanagawa, Japan
| | - Yuko Oguma
- Sports Medicine Research Center, Keio University, Kanagawa, Japan
| | - Hiroyuki Ishida
- Sports Medicine Research Center, Keio University, Kanagawa, Japan
| | - Naohiko Kohtake
- Graduate School of System Design and Management, Keio University, Kanagawa, Japan
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Assessment of Exercise-Associated Gastrointestinal Perturbations in Research and Practical Settings: Methodological Concerns and Recommendations for Best Practice. Int J Sport Nutr Exerc Metab 2022; 32:387-418. [PMID: 35963615 DOI: 10.1123/ijsnem.2022-0048] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/26/2022] [Accepted: 07/07/2022] [Indexed: 12/14/2022]
Abstract
Strenuous exercise is synonymous with disturbing gastrointestinal integrity and function, subsequently prompting systemic immune responses and exercise-associated gastrointestinal symptoms, a condition established as "exercise-induced gastrointestinal syndrome." When exercise stress and aligned exacerbation factors (i.e., extrinsic and intrinsic) are of substantial magnitude, these exercise-associated gastrointestinal perturbations can cause performance decrements and health implications of clinical significance. This potentially explains the exponential growth in exploratory, mechanistic, and interventional research in exercise gastroenterology to understand, accurately measure and interpret, and prevent or attenuate the performance debilitating and health consequences of exercise-induced gastrointestinal syndrome. Considering the recent advancement in exercise gastroenterology research, it has been highlighted that published literature in the area is consistently affected by substantial experimental limitations that may affect the accuracy of translating study outcomes into practical application/s and/or design of future research. This perspective methodological review attempts to highlight these concerns and provides guidance to improve the validity, reliability, and robustness of the next generation of exercise gastroenterology research. These methodological concerns include participant screening and description, exertional and exertional heat stress load, dietary control, hydration status, food and fluid provisions, circadian variation, biological sex differences, comprehensive assessment of established markers of exercise-induced gastrointestinal syndrome, validity of gastrointestinal symptoms assessment tool, and data reporting and presentation. Standardized experimental procedures are needed for the accurate interpretation of research findings, avoiding misinterpreted (e.g., pathological relevance of response magnitude) and overstated conclusions (e.g., clinical and practical relevance of intervention research outcomes), which will support more accurate translation into safe practice guidelines.
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Painelli VDS, Brietzke C, Franco-Alvarenga PE, Canestri R, Vinícius Í, Pires FO. A Narrative Review of Current Concerns and Future Perspectives of the Carbohydrate Mouth Rinse Effects on Exercise Performance. SAGE Open Med 2022; 10:20503121221098120. [PMID: 35615525 PMCID: PMC9125602 DOI: 10.1177/20503121221098120] [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: 12/24/2021] [Accepted: 04/13/2022] [Indexed: 11/16/2022] Open
Abstract
Previous systematic reviews have confirmed that carbohydrate (CHO) mouth rinse
may boost physical exercise performance, despite some methodological aspects
likely affecting its ergogenic effect. In this review, we discussed if the
exercise mode, pre-exercise fasting status, CHO solutions concentration, CHO
solutions temperature, mouth rinse duration, and CHO placebo effects may
potentially reduce the CHO mouth rinse ergogenic effect, suggesting possible
solutions to manage these potential confounders. The effectiveness of CHO mouth
rinse as a performance booster is apparently related to the origin of the
exercise-induced neuromuscular fatigue, as CHO mouth rinse unequivocally
potentiates endurance rather than sprint and strength exercises performance.
Furthermore, ergogenic effects have been greater in fasting than fed state,
somehow explaining the varied magnitude of the CHO mouth rinse effects in
exercise performance. In this regard, the CHO solution concentration and
temperature, as well as the mouth rinse duration, may have increased the
variability observed in CHO mouth rinse effects in fasting and fed state.
Finally, placebo effects have challenged the potential of the CHO mouth rinse as
an ergogenic aid. Therefore, we suggest that future studies should consider
methodological controls such as sample size and sample homogeneity, proper
familiarization with experimental procedures, and the use of alternative placebo
designs to provide unbiased evidence regarding the potential of the CHO mouth
rinse as an ergogenic aid.
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Affiliation(s)
- Vitor de Salles Painelli
- Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
- Strength Training Study and Research Group, Institute of Health Sciences, Paulista University, São Paulo, Brazil
| | - Cayque Brietzke
- Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
- Human Movement Science and Rehabilitation Program, Federal University of São Paulo, Santos, Brazil
| | - Paulo Estevão Franco-Alvarenga
- Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
- Human Movement Science and Rehabilitation Program, Federal University of São Paulo, Santos, Brazil
| | - Raul Canestri
- Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
| | - Ítalo Vinícius
- Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
| | - Flávio Oliveira Pires
- Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
- Human Movement Science and Rehabilitation Program, Federal University of São Paulo, Santos, Brazil
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Leow CHW, Tan B, Miyashita M, Lee JKW. Cultural differences in hydration practices among physically active individuals: a narrative review. J Int Soc Sports Nutr 2022; 19:150-163. [PMID: 35599916 PMCID: PMC9116399 DOI: 10.1080/15502783.2022.2057196] [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] [Indexed: 12/02/2022] Open
Abstract
It is well-established that appropriate hydration practices are essential in promoting health and optimizing performance and recovery. However, evidence-based hydration guidelines may not be adopted due to cultural differences across countries, such as religious beliefs, traditions, preferences, and beverage availability. Examples of hydration practices influenced by culture include beer consumption after sports in Western countries, consumption of sugarcane juice in India and Ramadan fasting among Muslims. For most cultural hydration practices, there is limited scientific evidence on their effects on rehydration, exercise performance, and recovery. Despite possible benefits of various hydration practices on exercise performance and recovery, they are inconsistent with current evidence-based hydration recommendations. More research on the impacts of cultural hydration differences on physiology, performance, and recovery is warranted to allow evidence-based guidelines and advisories. Abbreviations: ABV: alcohol by volume, ACSM: American College of Sports Medicine, NATA: National Athletic Trainers’ Association, ROS: reactive oxygen species, TCM: Traditional Chinese Medicine
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Affiliation(s)
- Clarence Hong Wei Leow
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, 2 Medical Drive, National University of Singapore, Singapore
- Campus for Research Excellence and Technological Enterprise (CREATE), Singapore
| | - Beverly Tan
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, 2 Medical Drive, National University of Singapore, Singapore
| | | | - Jason Kai Wei Lee
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, 2 Medical Drive, National University of Singapore, Singapore
- Campus for Research Excellence and Technological Enterprise (CREATE), Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- N.1 Institute for Health, National University of Singapore, Singapore
- Global Asia Institute, National University of Singapore, Singapore
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Effects of 24 h Compression Interventions with Different Garments on Recovery Markers during Running. Life (Basel) 2021; 11:life11090905. [PMID: 34575054 PMCID: PMC8471437 DOI: 10.3390/life11090905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/20/2021] [Accepted: 08/27/2021] [Indexed: 11/24/2022] Open
Abstract
Compression and temperature manipulation are discussed as strategies to improve performance markers and recovery in sports. Here, we investigate the effects of compression stockings made with fabric, either combined or not with heating and cooling substances, on variables related to running performance and recovery. Ten trained runners (mean ± standard deviation age 45 ± 9 years old, body mass 69 ± 7 kg, height 166 ± 4 cm) with no experience of using compression garments performed an intense running session of 10 km, then wore a stocking for 24 h (randomized; without compression, compression, compression with camphor, and compression with menthol), and were evaluated on the following day, after running 5 km. The different types of compression stockings used 24 h before exercise did not affect running kinematics (p > 0.14), skin temperature (p > 0.05), heart rate (p > 0.12; mean value of maximal heart rate 156 bpm), comfort perception (p = 0.13; mean value of 7/10 points), or perception of recovery (p = 0.13; mean value of 7/10 points). In general, there were no effects of 24 h pre-exercise lower leg compression, including those treated with menthol and camphor applications on running kinematics, skin temperature, heart rate, or recovery perception in athletes undertaking consecutive running exercises.
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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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Bose-O'Reilly S, Daanen H, Deering K, Gerrett N, Huynen MMTE, Lee J, Karrasch S, Matthies-Wiesler F, Mertes H, Schoierer J, Shumake-Guillemot J, van den Hazel P, Frank van Loenhout JA, Nowak D. COVID-19 and heat waves: New challenges for healthcare systems. ENVIRONMENTAL RESEARCH 2021; 198:111153. [PMID: 33857461 PMCID: PMC8056477 DOI: 10.1016/j.envres.2021.111153] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 03/26/2021] [Accepted: 04/06/2021] [Indexed: 05/12/2023]
Abstract
Heat waves and Covid-19 overlap, as this pandemic continues into summer 2021. Using a narrative review, we identified overlapping risk groups and propose coping strategies. The high-risk groups for heat-related health problems as well as for high-risk COVID-19 groups overlap considerably (elderly with pre-existing health conditions). Health care facilities will again be challenged by Covid-19 during heat waves. Health care personnel are also at risk of developing heat related health problems during hot periods due to the use of personal protective equipment to shield themselves from SARS-CoV-2 and must therefore be protected from excessive heat periods. Some existing recommendations for heat health protection contradict recommendations for COVID-19 protection. This paper provides a preliminary overview of possible strategies and interventions to tackle these ambiguities. The existing recommendations for protection against heat-related illnesses need revisions to determine whether they include essential aspects of infection control and occupational safety and how they may be supplemented.
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Affiliation(s)
- Stephan Bose-O'Reilly
- Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Ziemssenstr. 1, 80336, Munich, Germany; Institute for Public Health, Medical Decision Making and HTA, UMIT - Private University for Health Sciences, Medical Informatics and Technology, Eduard-Wallnöfer Zentrum 1, 6060, Hall i.T., Austria; University Children's Hospital Regensburg (KUNO) at the Hospital St. Hedwig of the Order of St. John and the University Hospital, University of Regensburg, Regensburg, Germany.
| | - Hein Daanen
- Department of Human Movement Sciences. Faculty of Behavioral and Movement Sciences. Vrije Universiteit Amsterdam. Van der Boechorststraat 7, 1081, BT Amsterdam, the Netherlands
| | - Katharina Deering
- Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Ziemssenstr. 1, 80336, Munich, Germany
| | - Nicola Gerrett
- Department of Human Movement Sciences. Faculty of Behavioral and Movement Sciences. Vrije Universiteit Amsterdam. Van der Boechorststraat 7, 1081, BT Amsterdam, the Netherlands
| | | | - Jason Lee
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore; Global Asia Institute, National University of Singapore, Singapore; N.1 Institute for Health, National University of Singapore, 28 Medical Dr, Singapore 117456, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Institute for Digital Medicine, National University of Singapore, Singapore; Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Stefan Karrasch
- Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Ziemssenstr. 1, 80336, Munich, Germany; Institute of Epidemiology, Helmholtz Zentrum München - German Research Centre for Environment and Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany; Comprehensive Pneumology Center Munich (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Franziska Matthies-Wiesler
- Institute of Epidemiology, Helmholtz Zentrum München - German Research Centre for Environment and Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Hanna Mertes
- Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Ziemssenstr. 1, 80336, Munich, Germany
| | - Julia Schoierer
- Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Ziemssenstr. 1, 80336, Munich, Germany
| | | | - Peter van den Hazel
- International Network on Children's Health, Environment and Safety (INCHES), Ellecom, the Netherlands
| | - Joris Adriaan Frank van Loenhout
- Centre for Research on the Epidemiology of Disasters (CRED), Institute of Health and Society, UCLouvain, Clos Chapelle-Aux-Champs 30, 1200, Woluwé-Saint-Lambert (Brussels), Belgium
| | - Dennis Nowak
- Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Ziemssenstr. 1, 80336, Munich, Germany; Comprehensive Pneumology Center Munich (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany
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Peel JS, McNarry MA, Heffernan SM, Nevola VR, Kilduff LP, Waldron M. The Effect of Dietary Supplements on Endurance Exercise Performance and Core Temperature in Hot Environments: A Meta-analysis and Meta-regression. Sports Med 2021; 51:2351-2371. [PMID: 34129223 PMCID: PMC8514372 DOI: 10.1007/s40279-021-01500-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND The ergogenic effects of dietary supplements on endurance exercise performance are well-established; however, their efficacy in hot environmental conditions has not been systematically evaluated. OBJECTIVES (1) To meta-analyse studies investigating the effects of selected dietary supplements on endurance performance and core temperature responses in the heat. Supplements were included if they were deemed to: (a) have a strong evidence base for 'directly' improving thermoneutral endurance performance, based on current position statements, or (b) have a proposed mechanism of action that related to modifiable factors associated with thermal balance. (2) To conduct meta-regressions to evaluate the moderating effect of selected variables on endurance performance and core temperature responses in the heat following dietary supplementation. METHODS A search was performed using various databases in May 2020. After screening, 25 peer-reviewed articles were identified for inclusion, across three separate meta-analyses: (1) exercise performance; (2) end core temperature; (3) submaximal core temperature. The moderating effect of several variables were assessed via sub-analysis and meta-regression. RESULTS Overall, dietary supplementation had a trivial significant positive effect on exercise performance (Hedges' g = 0.18, 95% CI 0.007-0.352, P = 0.042), a trivial non-significant positive effect on submaximal core temperature (Hedges' g = 0.18, 95% CI - 0.021 to 0.379, P = 0.080) and a small non-significant positive effect on end core temperature (Hedges' g = 0.20, 95% CI - 0.041 to 0.439, P = 0.104) in the heat. There was a non-significant effect of individual supplements on exercise performance (P = 0.973) and submaximal core temperature (P = 0.599). However, end core temperature was significantly affected by supplement type (P = 0.003), which was attributable to caffeine's large significant positive effect (n = 8; Hedges' g = 0.82, 95% CI 0.433-1.202, P < 0.001) and taurine's medium significant negative effect (n = 1; Hedges' g = - 0.96, 95% CI - 1.855 to - 0.069, P = 0.035). CONCLUSION Supplements such as caffeine and nitrates do not enhance endurance performance in the heat, with caffeine also increasing core temperature responses. Some amino acids might offer the greatest performance benefits in the heat. Exercising in the heat negatively affected the efficacy of many dietary supplements, indicating that further research is needed and current guidelines for performance in hot environments likely require revision.
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Affiliation(s)
- Jennifer S Peel
- A-STEM Centre, College of Engineering, Swansea University, Swansea, UK.
| | - Melitta A McNarry
- A-STEM Centre, College of Engineering, Swansea University, Swansea, UK
| | - Shane M Heffernan
- A-STEM Centre, College of Engineering, Swansea University, Swansea, UK
| | - Venturino R Nevola
- A-STEM Centre, College of Engineering, Swansea University, Swansea, UK
- Defence Science and Technology Laboratory (Dstl), Fareham, Hampshire, UK
| | - Liam P Kilduff
- A-STEM Centre, College of Engineering, Swansea University, Swansea, UK
- Welsh Institute of Performance Science, Swansea University, Swansea, UK
| | - Mark Waldron
- A-STEM Centre, College of Engineering, Swansea University, Swansea, UK
- Welsh Institute of Performance Science, Swansea University, Swansea, UK
- School of Science and Technology, University of New England, Armidale, NSW, Australia
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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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Paternoster N, Baggio E, Pelosi E. Personalized hydratation status in endurance and ultra-endurance: A review. MEDITERRANEAN JOURNAL OF NUTRITION AND METABOLISM 2020. [DOI: 10.3233/mnm-200434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This review aims to investigate the physiological mechanisms that underlie the hydro-electrolyte balance of the human body and the most appropriate hydration modalities for individuals involved in physical and sports activities, with a focus on ultra-endurance events. The role of effective hydration in achieving optimal sports performance is also investigated. An adequate pre-hydration is essential to perform physical and sporting activity in a condition of eu-hydration and to mantain physiologic levels of plasma electrolyte. To achieve these goals, athletes need to consume adequate drinks together with consuming meals and fluids, in order to provide an adequate absorption of the ingested fluids and the expulsion of those in excess through diuresis. Therefore, there are important differences between individuals in terms of sweating rates, the amount of electrolytes loss and the specific request of the discipline practiced and the sporting event to pursue.
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Affiliation(s)
- Nicolò Paternoster
- Centro di Medicina, Venice, Italy
- Centro Medico Fisioterapico, Magenta, Padova, Italy
| | | | - Ettore Pelosi
- Poliambulatorio Vitalia, Torino, Italy
- Centro PET Irmet – Affidea, Torino, Italy
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11
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Gogoi P, Li Z, Guo Z, Khuje S, An L, Hu Y, Chang S, Zhou C, Ren S. Ductile cooling phase change material. NANOSCALE ADVANCES 2020; 2:3900-3905. [PMID: 36132789 PMCID: PMC9419096 DOI: 10.1039/d0na00465k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 07/29/2020] [Indexed: 06/15/2023]
Abstract
Cooling represents a considerable fraction of energy consumption. However, it is indispensable to develop eco-friendly, biocompatible, and ductile cooling materials for personal applications. In this study, we demonstrate the ductile cooling ability with phase change of thermally passivated hydrogel composite materials with additive manufacturing ability. Thermal evaluation of such water-based composites indicates a superior cold retention capacity with a cooling comfort over 6 hours, while the composite displays a full recovery when strained up to 80% in uniaxial compression tests as a result of the intertwining between covalent and ionic bonds. A three-layered rectangular model was utilized to simulate the problem in a steady-state thermal analysis to study the cooling effect. Our findings indicate the potential of hydrogel as a cooling phase-change medium and its contribution towards ductile cooling applications.
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Affiliation(s)
- Pratahdeep Gogoi
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy Environment & Water Institute, University at Buffalo, The State University of New York Buffalo New York 14260 USA
| | - Zheng Li
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy Environment & Water Institute, University at Buffalo, The State University of New York Buffalo New York 14260 USA
- College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics Nanjing Jiangsu 210016 China
| | - Zipeng Guo
- Department of Industrial System Engineering, University at Buffalo, The State University of New York Buffalo New York 14260 USA
| | - Saurabh Khuje
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy Environment & Water Institute, University at Buffalo, The State University of New York Buffalo New York 14260 USA
| | - Lu An
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy Environment & Water Institute, University at Buffalo, The State University of New York Buffalo New York 14260 USA
| | - Yong Hu
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy Environment & Water Institute, University at Buffalo, The State University of New York Buffalo New York 14260 USA
| | - Shuquan Chang
- College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics Nanjing Jiangsu 210016 China
| | - Chi Zhou
- Department of Industrial System Engineering, University at Buffalo, The State University of New York Buffalo New York 14260 USA
| | - Shenqiang Ren
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy Environment & Water Institute, University at Buffalo, The State University of New York Buffalo New York 14260 USA
- Department of Chemistry, University at Buffalo, The State University of New York Buffalo New York 14260 USA
- Research and Education in Energy Environment & Water Institute, University at Buffalo, The State University of New York Buffalo New York 14260 USA
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12
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Daanen H, Bose-O'Reilly S, Brearley M, Flouris DA, Gerrett NM, Huynen M, Jones HM, Lee JKW, Morris N, Norton I, Nybo L, Oppermann E, Shumake-Guillemot J, Van den Hazel P. COVID-19 and thermoregulation-related problems: Practical recommendations. Temperature (Austin) 2020; 8:1-11. [PMID: 33553500 PMCID: PMC7849778 DOI: 10.1080/23328940.2020.1790971] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The COVID-19 pandemic started in the cold months of the year 2020 in the Northern hemisphere. Concerns were raised that the hot season may lead to additional problems as some typical interventions to prevent heat-related illness could potentially conflict with precautions to reduce coronavirus transmission. Therefore, an international research team organized by the Global Health Heat Information Network generated an inventory of the specific concerns about this nexus and began to address the issues. Three key thermal and covid-19 related topics were highlighted: 1) For the general public, going to public cool areas in the hot season interferes with the recommendation to stay at home to reduce the spread of the virus. Conflicting advice makes it necessary to revise national heat plans and alert policymakers of this forecasted issue. 2) For medical personnel working in hot conditions, heat strain is exacerbated due to a reduction in heat loss from wearing personal protective equipment to prevent contamination. To avoid heat-related injuries, medical personnel are recommended to precool and to minimize the increase in body core temperature using adopted work/rest schedules, specific clothing systems, and by drinking cold fluids. 3) Fever, one of the main symptoms of COVID-19, may be difficult to distinguish from heat-induced hyperthermia and a resting period may be necessary prior to measurement to avoid misinterpretation. In summary, heat in combination with the COVID-19 pandemic leads to additional problems; the impact of which can be reduced by revising heat plans and implementing special measures attentive to these compound risks.
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Affiliation(s)
- Hein Daanen
- Department of Human Movement Sciences. Faculty of Behavioral and Movement Sciences. Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Stephan Bose-O'Reilly
- Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Germany.,Institute for Public Health, Medical Decision Making and HTA, UMIT - Private University for Health Sciences, Medical Informatics and Technology, Hall i.T., Austria.,Hospital St. Hedwig of the Order of St. John, Institute and Clinic for Occupational, Social and Environmental Medicine, University Children's Hospital Regensburg (KUNO), University of Regensburg, Regensburg, Munich, Germany
| | - Matt Brearley
- National Critical Care and Trauma Response Centre, Australia
| | - D Andreas Flouris
- FAME Laboratory, Department of Exercise Science, University of Thessaly, Greece
| | - Nicola M Gerrett
- Department of Human Movement Sciences. Faculty of Behavioral and Movement Sciences. Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Maud Huynen
- Maastricht University Institute (MSI), Maastricht University, Maastricht, The Netherlands
| | - Hunter M Jones
- University Corporation for Atmospheric Research in Service to the U.S. National Oceanic & Atmospheric Administration, Silver Spring, MD, USA
| | - Jason Kai Wei Lee
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Global Asia Institute, National University of Singapore, Singapore.,N.1 Institute for Health, National University of Singapore, Singapore
| | | | - Ian Norton
- Respond Global, Australia.,Previously World Health Organization, Switzerland
| | - Lars Nybo
- University of Copenhagen, Copenhagen, Denmark
| | - Elspeth Oppermann
- Department Für Geographie, Ludwig-Maximilians-Universität München, Germany
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13
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Olcina G, Crespo C, Timón R, Mjaanes JM, Calleja-González J. Core Temperature Response During the Marathon Portion of the Ironman World Championship (Kona-Hawaii). Front Physiol 2019; 10:1469. [PMID: 31849714 PMCID: PMC6901617 DOI: 10.3389/fphys.2019.01469] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/14/2019] [Indexed: 11/22/2022] Open
Abstract
The Ironman triathlon consists of a 3.8 km swim, 180 km bike, and 42.195 km run. Thermoregulation responses play an important role in performance optimization and injury prevention. Factors such as environmental conditions including heat and humidity, athlete training level, and race duration can affect thermoregulation. Hyperthermia occurs when the core temperature rises above 38.5°C. The present study aims to describe core temperature (Tcore) in top-level and well-trained age group triathletes during the marathon of Ironman World Championship 2014 in Kona-Hawaii under thermal stress conditions. Tcore of 15 triathletes (age: 36.11 ± 7.36 years, body mass: 71.14 ± 7.12 kg, height: 179 ± 0.04 cm, and fat %: 8.48 ± 0.85) who classified for the Ironman World Championship was measured by an ingestible pill telemetry system prior to competition, during the marathon and 60 min after finishing the race. Mean wet bulb globe temperature (WBGT) during the marathon was 24.66°C (range 22.44–28.50°C). Body mass index (BMI) and perceived exertion (Borg Scale and Visual Analog Scale-Pain) were collected before the race and 60 min after the event. Time variables were extracted from their official race time and split times. Finish time was 10: 06:56 ± 0:48:30. Tcore was initially 36.62 ± 0.17°C, increased at the end of the event (38.55 ± 0.64; p < 0.01) and remained elevated 60 min after the event (38.65 ± 0.41°C; p < 0.002). BMI significantly decreased after the event (22.85 ± 1.11 vs. 21.73 ± 1.36; p < 0.05), whereas both exercise perceived exertion [Borg Scale (10.2 ± 1.64 vs. 18.60 ± 1.67; p < 0.003)] and perceived muscle pain [VAS Pain (2.75 ± 1.59 vs. 9.08 ± 1.13; p < 0.001)] increased significantly after the event. Tcore during competition correlated negatively with position in age group (r − 0.949, p = 0.051), but not with race time (r = −0.817; p = 0.183). High-level age group triathletes competing under thermal stress conditions in the Kona Ironman reached a state of hyperthermia during the marathon. After 60 min of recovery the hyperthermia persisted. Strategies to aid post-event cooling and recovery should be considered to avoid the potentially dangerous adverse health effects of hyperthermia.
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Affiliation(s)
- Guillermo Olcina
- Research Group in Sport Training and Physical Conditioning (GAEDAF), Faculty of Sport Sciences, University of Extremadura, Cáceres, Spain
| | - Carmen Crespo
- Research Group in Sport Training and Physical Conditioning (GAEDAF), Faculty of Sport Sciences, University of Extremadura, Cáceres, Spain
| | - Rafael Timón
- Research Group in Sport Training and Physical Conditioning (GAEDAF), Faculty of Sport Sciences, University of Extremadura, Cáceres, Spain
| | - Jeffrey M Mjaanes
- Department of Orthopaedics, Northwestern University, Chicago, IL, United States
| | - Julio Calleja-González
- Department of Physical Education and Sports, University of the Basque Country (UPV-EHU), Vitoria, Spain
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14
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Kjellstrom T, Lemke B, Lee J. Workplace Heat: An increasing threat to occupational health and productivity. Am J Ind Med 2019; 62:1076-1078. [PMID: 31595541 DOI: 10.1002/ajim.23051] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 01/20/2023]
Affiliation(s)
- Tord Kjellstrom
- National Center for Epidemiology and Population HealthAustralian National University Canberra Australian Capital Territory Australia
- HEAT‐SHIELD project, Center for Technology Research and Innovation Ltd, (CETRI) Limassol Cyprus
- Health and Environment International Trust Mapua New Zealand
| | - Bruno Lemke
- Health and Environment International Trust Mapua New Zealand
- School of BusinessNelson‐Marlborough Institute of Technology Nelson New Zealand
| | - Jason Lee
- Department of PhysiologyYong Loo Lin School of Medicine, National University of Singapore Singapore Singapore
- Global Asia InstituteNational University of Singapore Singapore Singapore
- N.1 Institute for HealthNational University of Singapore Singapore Singapore
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15
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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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16
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Recycled Cellulose Aerogels from Paper Waste for a Heat Insulation Design of Canteen Bottles. FLUIDS 2019. [DOI: 10.3390/fluids4030174] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Exercising in a tropical climate with constant high temperatures and high humidity increases the risk of heatstroke for active people who frequently train outdoors. For these active persons, a cooling source of water nearby can be essential, and this is usually carried in canteen bottles. However, commercially available water canteen bottles have limited thermal insulation capability to keep the liquid content cooled for the required period. This work proposed an engineering solution to enhance the heat insulation performance of water canteen bottles, using recycled cellulose aerogels made from paper waste for the first time as an insulating layer. Recycled cellulose aerogels wrapped around the water canteen bottle provides excellent thermal insulation performance, while not adding significant weight to the bottle. The temperature of the ice slurry in the canteen bottle was measured periodically over four hours with a mercury thermometer. The effects of the static and dynamic conditions on the temperature rate were also quantified. A 1.5 cm thickness of 1.0 wt.% recycled cellulose aerogel wrapped around the canteen bottle can provide an excellent thermal insulation performance with the lowest rise in temperature, achieving a low final temperature of the ice slurry content of 3.5 °C after 4 h. This result is much better than that provided by available commercial bottles under the same conditions.
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17
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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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18
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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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19
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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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20
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Onitsuka S, Nakamura D, Onishi T, Arimitsu T, Takahashi H, Hasegawa H. Ice slurry ingestion reduces human brain temperature measured using non-invasive magnetic resonance spectroscopy. Sci Rep 2018; 8:2757. [PMID: 29426888 PMCID: PMC5807509 DOI: 10.1038/s41598-018-21086-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 01/29/2018] [Indexed: 11/09/2022] Open
Abstract
We previously reported that ice slurry ingestion reduced forehead skin temperature, thereby potentially reducing brain temperature (Tbrain). Therefore, in the current study, we investigated the effect of ice slurry ingestion on Tbrain using proton magnetic resonance spectroscopy, which is a robust, non-invasive method. Eight male participants ingested 7.5 g/kg of either a thermoneutral drink (37 °C; CON) or ice slurry (-1 °C; ICE) for about 5 min following a 15-min baseline period. Then, participants remained at rest for 30 min. As physiological indices, Tbrain, rectal temperature (Tre), mean skin temperature, nude body mass, and urine specific gravity were measured. Subjective thermal sensation (TS) and thermal comfort (TC) were measured before and after the experiment. Tbrain and Tre significantly reduced after ingestion of ICE compared with after ingestion of CON, and there was a significant correlation between Tbrain and Tre. The other physiological indices were not significantly different between beverage conditions. TS and TC were significantly lower with ICE than with CON (p < 0.05). These results indicate that ice slurry ingestion can cool the brain, as well as the body's core.
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Affiliation(s)
- Sumire Onitsuka
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashihiroshima, 739-8521, Japan.,Japan Society for the Promotion of Science, Tokyo, 102-0083, Japan
| | | | | | - Takuma Arimitsu
- College of Sport and Health Science, Ritsumeikan University, Kusatsu, 525-8577, Japan
| | | | - Hiroshi Hasegawa
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashihiroshima, 739-8521, Japan.
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21
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Should Workers Avoid Consumption of Chilled Fluids in a Hot and Humid Climate? Saf Health Work 2017; 8:327-328. [PMID: 29276629 PMCID: PMC5715486 DOI: 10.1016/j.shaw.2017.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/02/2017] [Accepted: 07/04/2017] [Indexed: 12/04/2022] Open
Abstract
Despite provision of drinking water as the most common method of occupational heat stress prevention, there remains confusion in hydration messaging to workers. During work site interactions in a hot and humid climate, workers commonly report being informed to consume tepid fluids to accelerate rehydration. When questioned on the evidence supporting such advice, workers typically cite that fluid absorption is delayed by ingestion of chilled beverages. Presumably, delayed absorption would be a product of fluid delivery from the gut to the intestines, otherwise known as gastric emptying. Regulation of gastric emptying is multifactorial, with gastric volume and beverage energy density the primary factors. If gastric emptying is temperature dependent, the impact of cooling is modest in both magnitude and duration (≤ 5 minutes) due to the warming of fluids upon ingestion, particularly where workers have elevated core temperature. Given that chilled beverages are most preferred by workers, and result in greater consumption than warm fluids during and following physical activity, the resultant increased consumption of chilled fluids would promote gastric emptying through superior gastric volume. Hence, advising workers to avoid cool/cold fluids during rehydration appears to be a misinterpretation of the research. More appropriate messaging to workers would include the thermal benefits of cool/cold fluid consumption in hot and humid conditions, thereby promoting autonomy to trial chilled beverages and determine personal preference. In doing so, temperature-based palatability would be maximized and increase the likelihood of workers maintaining or restoring hydration status during and after their work shift.
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22
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Morris NB, Jay O. Staying warm in the cold with a hot drink: The role of visceral thermoreceptors. Temperature (Austin) 2017; 4:123-125. [PMID: 28680927 DOI: 10.1080/23328940.2017.1299667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Nathan B Morris
- Thermal Ergonomics Laboratory, Faculty of Health Sciences, University of Sydney, Sydney, NSW, Australia
| | - Ollie Jay
- Thermal Ergonomics Laboratory, Faculty of Health Sciences University of Sydney, K216, 75 East Street Lidcombe, NSW 2141, Australia.,Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
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23
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Cheung SS, Lee JKW, Oksa J. Thermal stress, human performance, and physical employment standards. Appl Physiol Nutr Metab 2017; 41:S148-64. [PMID: 27277564 DOI: 10.1139/apnm-2015-0518] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many physically demanding occupations in both developed and developing economies involve exposure to extreme thermal environments that can affect work capacity and ultimately health. Thermal extremes may be present in either an outdoor or an indoor work environment, and can be due to a combination of the natural or artificial ambient environment, the rate of metabolic heat generation from physical work, processes specific to the workplace (e.g., steel manufacturing), or through the requirement for protective clothing impairing heat dissipation. Together, thermal exposure can elicit acute impairment of work capacity and also chronic effects on health, greatly contributing to worker health risk and reduced productivity. Surprisingly, in most occupations even in developed economies, there are rarely any standards regarding enforced heat or cold safety for workers. Furthermore, specific physical employment standards or accommodations for thermal stressors are rare, with workers commonly tested under near-perfect conditions. This review surveys the major occupational impact of thermal extremes and existing employment standards, proposing guidelines for improvement and areas for future research.
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Affiliation(s)
- Stephen S Cheung
- a Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada
| | - Jason K W Lee
- b Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore.,c Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,d Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Juha Oksa
- e Finnish Institute of Occupational Health, Physical Work Capacity team, Oulu, Finland
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24
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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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25
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Affiliation(s)
- Nathan B Morris
- Thermal Ergonomics Laboratory, Faculty of Health Sciences, University of Sydney , NSW, Australia
| | - Ollie Jay
- Thermal Ergonomics Laboratory, Faculty of Health Sciences, University of Sydney , NSW, Australia
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26
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Périard JD, Racinais S. Training and competing in the heat. Scand J Med Sci Sports 2016; 25 Suppl 1:2-3. [PMID: 25943651 DOI: 10.1111/sms.12448] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J D Périard
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
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27
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Lee JK, Kenefick RW, Cheuvront SN. Novel Cooling Strategies for Military Training and Operations. J Strength Cond Res 2015; 29 Suppl 11:S77-81. [DOI: 10.1519/jsc.0000000000001086] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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