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Foot Cooling between Interval Bouts Enhances Repeated Lower Limb Power Performance: The Role of Delaying Fatigue. J Hum Kinet 2023; 86:107-116. [PMID: 37181265 PMCID: PMC10170544 DOI: 10.5114/jhk/159623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
This study aimed to investigate whether interbout foot cooling (FC) may enhance repeated lower limb power performance and the corresponding physiological responses based on interset FC, which has been demonstrated to enhance leg-press performance. In a repeated-measures crossover design, ten active men (aged 21.5 ± 1.5 years, exercising >3 times per week) performed four bouts of 10-s cycle ergometer sprints with interbout FC at 10°C water for 2.5 min or non-cooling (NC) with a 5-day interval. The results indicated that FC elicited higher total work (27.57 ± 5.66 kJ vs. 26.55 ± 5.76 kJ) and arousal scores than NC (p < 0.05). Furthermore, under the NC condition, participants decreased mean power (p < 0.05) with no alteration of vastus lateralis (VL) electromyography (EMG) activities after the second bout; whereas under the FC condition, participants maintained steady mean power accompanied by increased VL EMG activities in the last two bouts (p < 0.05). Jointly, participants had higher mean power ([3rd = 10.14 ± 1.15 vs. 9.37 ± 1.30; 4th= 9.79 ± 1.22 vs. 9.23 ± 1.27] W/kg) and VL EMG activities in the last two bouts under the FC than NC condition (p < 0.05). However, perceived exertion and the heart rate were comparable between the two conditions (p > 0.05). In conclusion, interbout FC elicited a higher arousal level and repeated lower limb power performance, which could be explained by delaying peripheral fatigue via increasing excitatory drive and recruiting additional motor units to compensate for fatigue-related responses and power decrements.
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Douzi W, Dugué B, Vinches L, Al Sayed C, Hallé S, Bosquet L, Dupuy O. Cooling during exercise enhances performances, but the cooled body areas matter: A systematic review with meta‐analyses. Scand J Med Sci Sports 2019; 29:1660-1676. [DOI: 10.1111/sms.13521] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 07/10/2019] [Accepted: 07/17/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Wafa Douzi
- Laboratoire Mobilité Vieillissement Exercice (MOVE)‐EA6314, Faculty of Sport Sciences University of Poitiers Poitiers France
| | - Benoit Dugué
- Laboratoire Mobilité Vieillissement Exercice (MOVE)‐EA6314, Faculty of Sport Sciences University of Poitiers Poitiers France
| | - Ludwig Vinches
- Department of Mechanical Engineering ‐ Ecole de Technologie Supérieure Montréal QC Canada
| | - Chady Al Sayed
- Department of Mechanical Engineering ‐ Ecole de Technologie Supérieure Montréal QC Canada
| | - Stéphane Hallé
- Department of Mechanical Engineering ‐ Ecole de Technologie Supérieure Montréal QC Canada
| | - Laurent Bosquet
- Laboratoire Mobilité Vieillissement Exercice (MOVE)‐EA6314, Faculty of Sport Sciences University of Poitiers Poitiers France
| | - Olivier Dupuy
- Laboratoire Mobilité Vieillissement Exercice (MOVE)‐EA6314, Faculty of Sport Sciences University of Poitiers Poitiers France
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Maroni T, Dawson B, Landers G, Naylor L, Wallman K. Hand and torso pre-cooling does not enhance subsequent high-intensity cycling or cognitive performance in heat. Temperature (Austin) 2019; 7:165-177. [PMID: 33015244 PMCID: PMC7518759 DOI: 10.1080/23328940.2019.1631731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 06/06/2019] [Accepted: 06/08/2019] [Indexed: 10/26/2022] Open
Abstract
The purpose of this study was to compare the separate and combined effects of two practical cooling methods (hand and torso) used prior to exercise on subsequent high-intensity cycling performance in heat. Ten trained male cyclists (V̇O2peak: 65.7 ± 10.7 ml.kg-1.min-1) performed four experimental trials (randomised within-subjects design) involving 30-min of pre-cooling (20-min seated; PRE-COOL, 10 min warm-up; PRE-COOL+WUP), while using a: (1) hand-cooling glove (CG); (2) cooling jacket (CJ); (3) both CG and CJ (CG+J); or (4) no-cooling (NC) control, followed by a cycling race simulation protocol (all performed in 35.0 ± 0.6°C and 56.6 ± 4.5% RH). During the 30-min of pre-cooling, no reductions in core (Tc) or mean skin temperature (Tsk) occurred; however, Tsk remained lower in the CJ and CG+J trials compared to NC and CG (p = 0.002-0.040, d= 0.55-1.01). Thermal sensation ratings also indicated that participants felt "hotter" during NC compared to all other trials during both PRE-COOL and PRE-COOL+WUP (p = 0.001-0.015, d= 1.0-2.19), plus the early stages of exercise (sets 1-2; p = 0.005-0.050, d= 0.56-1.22). Following cooling, no differences were found for absolute Tc and Tsk responses between trials over the entire exercise protocol (p > 0.05). Exercise and cognitive (working memory) performance also did not differ between trials (p = 0.843); however, cognitive performance improved over time in all trials (p < 0.001). In summary, pre-cooling (20-min seated and 10-min warm-up) in heat did not improve subsequent high-intensity cycling performance, cognitive responses and associated thermoregulatory strain (Tc and Tsk) compared to control.
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Affiliation(s)
- Tessa Maroni
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Australia
| | - Brian Dawson
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Australia
| | - Grant Landers
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Australia
| | - Louise Naylor
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Australia
| | - Karen Wallman
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Australia
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Dhahbi W, Sellami M, Chaouachi A, Padulo J, Milic M, Mekki I, Chamari K. Seasonal weather conditions affect training program efficiency and physical performance among special forces trainees: A long-term follow-up study. PLoS One 2018; 13:e0206088. [PMID: 30335826 PMCID: PMC6193725 DOI: 10.1371/journal.pone.0206088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/01/2018] [Indexed: 11/18/2022] Open
Abstract
The purpose of the present investigation was to follow-up the effect of specific commandos' training-cycles (SCTCs) on upper-body strength resistance and running endurance performance, as well as determine whether variation in seasonal parameters has any effect on physical performance. Fourteen SCTCs were held over eight years, involving 466 participants. Participants were assigned to four subgroups according to their distribution over the seasons: summer (n = 124), autumn (n = 145), winter (n = 52) and spring (n = 145). Before and after each SCTC, four tests (maximal pull-up, push-up and sit-up repetitions in 70-seconds for muscle strength resistance) and a 5-km cross-country run (endurance) were performed. Seasonal data were continuously recorded during all SCTCs. Body mass decreased significantly (p<0.05) in all groups following SCTCs. These training-cycles induced a significant increase (p<0.05) in the 70-seconds push-ups, pull-ups and sit-ups and a decrease (p<0.01) in the 5-km cross-country running time among all trainees. The main effect of the season was present in all tests (p<0.01). With regard to the percentage of changes, the results from the 70-seconds push-up, pull-up and sit-up tests were significantly higher in winter and spring (p<0.01) compared with the two other seasons, while 5-km cross-country performance improvements were significantly higher (p<0.01) in spring and summer, compared to the two other seasons. In summary,14-week of SCTCs improved upper-body strength resistance and running endurance performance in the commandos. Improvements in strength resistance performance were greater during cool weather (winter and spring), while improvements in running endurance performance were higher during hotter (spring and summer) seasons.
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Affiliation(s)
- Wissem Dhahbi
- Tunisian Research Laboratory “Sport Performance Optimisation”, National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia
- Qatar Police College, Training Department, Doha, Qatar
- Tunisian National Guard Commandos School, Oued Zarga, Tunisia
- University of Qatar, College of Arts and Sciences (Qu-CAS), Sport Science Program (SSP), Doha, Qatar
| | - Maha Sellami
- University of Qatar, College of Arts and Sciences (Qu-CAS), Sport Science Program (SSP), Doha, Qatar
| | - Anis Chaouachi
- Tunisian Research Laboratory “Sport Performance Optimisation”, National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia
| | - Johnny Padulo
- Tunisian Research Laboratory “Sport Performance Optimisation”, National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia
- University eCampus, Novedrate, Italy
- University of Split, Faculty of Kinesiology, Split, Croatia
| | - Mirjana Milic
- University of Split, Faculty of Kinesiology, Split, Croatia
| | - Imed Mekki
- Tunisian National Guard Commandos School, Oued Zarga, Tunisia
| | - Karim Chamari
- Athlete Health and Performance Research Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
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Racinais S, Cocking S, Périard JD. Sports and environmental temperature: From warming-up to heating-up. Temperature (Austin) 2017; 4:227-257. [PMID: 28944269 DOI: 10.1080/23328940.2017.1356427] [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] [Received: 05/09/2017] [Revised: 07/09/2017] [Accepted: 07/09/2017] [Indexed: 01/22/2023] Open
Abstract
Most professional and recreational athletes perform pre-conditioning exercises, often collectively termed a 'warm-up' to prepare for a competitive task. The main objective of warming-up is to induce both temperature and non-temperature related responses to optimize performance. These responses include increasing muscle temperature, initiating metabolic and circulatory adjustments, and preparing psychologically for the upcoming task. However, warming-up in hot and/or humid ambient conditions increases thermal and circulatory strain. As a result, this may precipitate neuromuscular and cardiovascular impairments limiting endurance capacity. Preparations for competing in the heat should include an acclimatization regimen. Athletes should also consider cooling interventions to curtail heat gain during the warm-up and minimize dehydration. Indeed, although it forms an important part of the pre-competition preparation in all environmental conditions, the rise in whole-body temperature should be limited in hot environments. This review provides recommendations on how to build an effective warm-up following a 3 stage RAMP model (Raise, Activate and Mobilize, Potentiate), including general and context specific exercises, along with dynamic flexibility work. In addition, this review provides suggestion to manipulate the warm-up to suit the demands of competition in hot environments, along with other strategies to avoid heating-up.
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Affiliation(s)
- Sébastien Racinais
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar.,French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, France
| | - Scott Cocking
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar.,Research Institute for Sport and Exercise Science, Liverpool John Moores University, United Kingdom
| | - Julien D Périard
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar.,University of Canberra, Research Institute for Sport and Exercise, Canberra, Australia
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Bongers CCWG, Hopman MTE, Eijsvogels TMH. Cooling interventions for athletes: An overview of effectiveness, physiological mechanisms, and practical considerations. Temperature (Austin) 2017; 4:60-78. [PMID: 28349095 PMCID: PMC5356217 DOI: 10.1080/23328940.2016.1277003] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/22/2016] [Accepted: 12/22/2016] [Indexed: 02/08/2023] Open
Abstract
Exercise-induced increases in core body temperature could negative impact performance and may lead to development of heat-related illnesses. The use of cooling techniques prior (pre-cooling), during (per-cooling) or directly after (post-cooling) exercise may limit the increase in core body temperature and therefore improve exercise performance. The aim of the present review is to provide a comprehensive overview of current scientific knowledge in the field of pre-cooling, per-cooling and post-cooling. Based on existing studies, we will discuss 1) the effectiveness of cooling interventions, 2) the underlying physiological mechanisms and 3) practical considerations regarding the use of different cooling techniques. Furthermore, we tried to identify the optimal cooling technique and compared whether cooling-induced performance benefits are different between cool, moderate and hot ambient conditions. This article provides researchers, physicians, athletes and coaches with important information regarding the implementation of cooling techniques to maintain exercise performance and to successfully compete in thermally stressful conditions.
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Affiliation(s)
- Coen C W G Bongers
- Radboud Institute of Health Sciences, Radboud university medical center, Department of Physiology , Nijmegen, The Netherlands
| | - Maria T E Hopman
- Radboud Institute of Health Sciences, Radboud university medical center, Department of Physiology , Nijmegen, The Netherlands
| | - Thijs M H Eijsvogels
- Radboud Institute of Health Sciences, Radboud university medical center, Department of Physiology, Nijmegen, The Netherlands; Research Institute for Sports and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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Willmott AGB, Bliss A, Simpson WH, Tocker SM, Cottingham R, Maxwell NS. CAERvest® - a novel endothermic hypothermic device for core temperature cooling: safety and efficacy testing. INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFETY AND ERGONOMICS 2016; 24:118-128. [PMID: 27997307 DOI: 10.1080/10803548.2016.1273640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
INTRODUCTION Cooling of the body is used to treat hyperthermic individuals with heatstroke or to depress core temperature below normal for neuroprotection. A novel, chemically activated, unpowered cooling device, CAERvest®, was investigated for safety and efficacy. METHODS Eight healthy male participants (body mass 79.9 ± 1.9 kg and body fat percentage 16.1 ± 3.8%) visited the laboratory (20 °C, 40% relative humidity) on four occasions. Following 30-min rest, physiological and perceptual measures were recorded. Participants were then fitted with the CAERvest® proof of concept (PoC) or prototype 1 (P1), 2 (P2) or 3 (P3) for 60 min. Temperature, cardiovascular and perceptual measures were recorded every 5 min. After cooling, the CAERvest® was removed and the torso checked for cold-related injuries. RESULTS Temperature measures significantly (p < 0.05) reduced pre to post in all trials. Larger reductions in core and skin temperatures were observed for PoC (-0.36 ± 0.18 and -1.55 ± 0.97 °C) and P3 (-0.36 ± 0.22 and -2.47 ± 0.82 °C), compared with P1 and P2. No signs of cold-related injury were observed at any stage. CONCLUSION This study demonstrates that the CAERvest® is an effective device for reducing body temperature in healthy normothermic individuals without presence of cold injury. Further research in healthy and clinical populations is warranted.
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Affiliation(s)
- Ashley G B Willmott
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
| | - Alex Bliss
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
| | | | | | | | - Neil S Maxwell
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
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Abstract
Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimize performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimize performance is to heat acclimatize. Heat acclimatization should comprise repeated exercise–heat exposures over 1–2 weeks. In addition, athletes should initiate competition and training in an euhydrated state and minimize dehydration during exercise. Following the development of commercial cooling systems (e.g., cooling vests), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organizers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimizing the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events for hydration and body cooling opportunities when competitions are held in the heat.
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Abstract
Cooling strategies that help prevent a reduction in exercise capacity whilst exercising in the heat have received considerable research interest over the past 3 decades, especially in the lead up to a relatively hot Olympic and Paralympic Games. Progressing into the next Olympic/Paralympic cycle, the host, Rio de Janeiro, could again present an environmental challenge for competing athletes. Despite the interest and vast array of research into cooling strategies for the able-bodied athlete, less is known regarding the application of these cooling strategies in the thermoregulatory impaired spinal cord injured (SCI) athletic population. Individuals with a spinal cord injury (SCI) have a reduced afferent input to the thermoregulatory centre and a loss of both sweating capacity and vasomotor control below the level of the spinal cord lesion. The magnitude of this thermoregulatory impairment is proportional to the level of the lesion. For instance, individuals with high-level lesions (tetraplegia) are at a greater risk of heat illness than individuals with lower-level lesions (paraplegia) at a given exercise intensity. Therefore, cooling strategies may be highly beneficial in this population group, even in moderate ambient conditions (~21 °C). This review was undertaken to examine the scientific literature that addresses the application of cooling strategies in individuals with an SCI. Each method is discussed in regards to the practical issues associated with the method and the potential underlying mechanism. For instance, site-specific cooling would be more suitable for an athlete with an SCI than whole body water immersion, due to the practical difficulties of administering this method in this population group. From the studies reviewed, wearing an ice vest during intermittent sprint exercise has been shown to decrease thermal strain and improve performance. These garments have also been shown to be effective during exercise in the able-bodied. Drawing on additional findings from the able-bodied literature, the combination of methods used prior to and during exercise and/or during rest periods/half-time may increase the effectiveness of a strategy. However, due to the paucity of research involving athletes with an SCI, it is difficult to establish an optimal cooling strategy. Future studies are needed to ensure that research outcomes can be translated into meaningful performance enhancements by investigating cooling strategies under the constraints of actual competition. Cooling strategies that meet the demands of intermittent wheelchair sports need to be identified, with particular attention to the logistics of the sport.
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Racinais S, Alonso JM, Coutts AJ, Flouris AD, Girard O, González-Alonso J, Hausswirth C, Jay O, Lee JKW, Mitchell N, Nassis GP, Nybo L, Pluim BM, Roelands B, Sawka MN, Wingo J, Périard JD. Consensus recommendations on training and competing in the heat. Br J Sports Med 2015; 49:1164-73. [PMID: 26069301 PMCID: PMC4602249 DOI: 10.1136/bjsports-2015-094915] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2015] [Indexed: 11/05/2022]
Abstract
Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimise performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimise performance is to heat acclimatise. Heat acclimatisation should comprise repeated exercise-heat exposures over 1–2 weeks. In addition, athletes should initiate competition and training in a euhydrated state and minimise dehydration during exercise. Following the development of commercial cooling systems (eg, cooling-vest), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organisers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimising the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events, for hydration and body cooling opportunities, when competitions are held in the heat.
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Affiliation(s)
- S Racinais
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - J M Alonso
- Sports Medicine Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar Medical and Anti-doping Commission, International Association of Athletics Federations (IAAF), Montecarlo, Monaco
| | - A J Coutts
- Sport and Exercise Discipline Group, University of Technology Sydney (UTS), Australia
| | - A D Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - O Girard
- Department of Physiology, Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - J González-Alonso
- Department of Life Sciences, Centre for Sports Medicine and Human Performance, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
| | - C Hausswirth
- Research Department, Laboratory of Sport, Expertise and Performance, French National Institute of Sport (INSEP), Paris, France
| | - O Jay
- Discipline of Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Lidcombe, Australia
| | - J K W Lee
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - N Mitchell
- British Cycling and 'Sky Pro Cycling', National Cycling Centre, Manchester, UK
| | - G P Nassis
- National Sports Medicine Programme, Excellence in Football Project, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - L Nybo
- Department of Nutrition, Exercise and Sport, Section of Human Physiology, University of Copenhagen, Copenhagen, Denmark
| | - B M Pluim
- Medical Department, Royal Netherlands Lawn Tennis Association (KNLTB), Amersfoort, The Netherlands
| | - B Roelands
- Department of Human Physiology, Vrije Universiteit Brussel, Brussels, Belgium
| | - M N Sawka
- School of Applied Physiology, College of Science, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - J Wingo
- Department of Kinesiology, University of Alabama, Tuscaloosa, USA
| | - J D Périard
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
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Racinais S, Alonso JM, Coutts AJ, Flouris AD, Girard O, González-Alonso J, Hausswirth C, Jay O, Lee JKW, Mitchell N, Nassis GP, Nybo L, Pluim BM, Roelands B, Sawka MN, Wingo JE, Périard JD. Consensus recommendations on training and competing in the heat. Scand J Med Sci Sports 2015; 25 Suppl 1:6-19. [DOI: 10.1111/sms.12467] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2015] [Indexed: 11/26/2022]
Affiliation(s)
- S. Racinais
- Athlete Health and Performance Research Centre; Aspetar; Qatar Orthopaedic and Sports Medicine Hospital; Doha Qatar
| | - J. M. Alonso
- Sports Medicine Department; Aspetar Orthopaedic and Sports Medicine Hospital; Doha Qatar
- Medical and Anti-doping Commission; International Association of Athletics Federations (IAAF); Montecarlo Monaco
| | - A. J. Coutts
- Sport and Exercise Discipline Group; University of Technology Sydney (UTS); Lindfield New South Wales Australia
| | - A. D. Flouris
- FAME Laboratory; Department of Physical Education and Sport Science; University of Thessaly; Trikala Greece
| | - O. Girard
- ISSUL; Institute of Sport Sciences; Department of Physiology; Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - J. González-Alonso
- Centre for Sports Medicine and Human Performance; Department of Life Sciences; College of Health and Life Sciences; Brunel University London; Uxbridge UK
| | - C. Hausswirth
- French National Institute of Sport (INSEP); Research Department; Laboratory of Sport, Expertise and Performance; Paris France
| | - O. Jay
- Discipline of Exercise and Sport Science; Faculty of Health Sciences; University of Sydney; Lidcombe New South Wales Australia
| | - J. K. W. Lee
- Defence Medical and Environmental Research Institute; DSO National Laboratories; Singapore
- Yong Loo Lin School of Medicine; National University of Singapore; Singapore
- Lee Kong Chian School of Medicine; Nanyang Technological University; Singapore
| | - N. Mitchell
- British Cycling and “Sky Pro Cycling”; National Cycling Centre; Manchester UK
| | - G. P. Nassis
- National Sports Medicine Programme; Excellence in Football Project; Aspetar; Qatar Orthopaedic and Sports Medicine Hospital; Doha Qatar
| | - L. Nybo
- Department of Nutrition, Exercise and Sport; Section of Human Physiology; University of Copenhagen; Copenhagen Denmark
| | - B. M. Pluim
- Medical Department; Royal Netherlands Lawn Tennis Association (KNLTB); Amersfoort The Netherlands
| | - B. Roelands
- Department of Human Physiology; Vrije Universiteit Brussel; Brussels Belgium
| | - M. N. Sawka
- School of Applied Physiology; College of Science; Georgia Institute of Technology; Atlanta Georgia USA
| | - J. E. Wingo
- Department of Kinesiology; University of Alabama; Tuscaloosa Alabama USA
| | - J. D. Périard
- Athlete Health and Performance Research Centre; Aspetar; Qatar Orthopaedic and Sports Medicine Hospital; Doha Qatar
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Girard O, Brocherie F, Bishop DJ. Sprint performance under heat stress: A review. Scand J Med Sci Sports 2015; 25 Suppl 1:79-89. [DOI: 10.1111/sms.12437] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2015] [Indexed: 11/29/2022]
Affiliation(s)
- O. Girard
- ISSUL; Institute of Sport Sciences; Department of Physiology; Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - F. Brocherie
- ISSUL; Institute of Sport Sciences; Department of Physiology; Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - D. J. Bishop
- Institute of Sport; Exercise and Active Living (ISEAL); College of Sport and Exercise Science; Victoria University; Melbourne Victoria Australia
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Taylor L, Mauger AR, Watkins SL, Fitch N, Brewer J, Maxwell NS, Webborn N, Castle PC. Precooling Does Not Improve 2,000-m Rowing Performance of Females in Hot, Humid Conditions. J Strength Cond Res 2014; 28:3416-24. [DOI: 10.1519/jsc.0000000000000558] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Pryor RR, Suyama J, Guyette FX, Reis SE, Hostler D. The effects of ice slurry ingestion before exertion in Wildland firefighting gear. PREHOSP EMERG CARE 2014; 19:241-6. [PMID: 25290244 DOI: 10.3109/10903127.2014.959221] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To investigate the effect of ice slurry ingestion precooling on body core temperature (Tc) during exertion in wildland firefighting garments in uncompensable heat stress. METHODS On two separate trials, 10 males ingested 7.5 g·kg(-1) of either an ice slurry (0.1°C) or control beverage (20°C) during seated rest for 30 minutes prior to simulating the U.S. Forest Service Pack Test on a treadmill in wildland firefighting garments in a hot environment (38.8 ± 1.2°C, 17.5 ± 1.4% relative humidity). Deep gastric temperature, mean skin temperature (Tsk), and heart rate (HR) were recorded. Ratings of perceived exertion, thermal sensation, comfort, and sweating were assessed. RESULTS Compared with ingestion of a temperate beverage, precooling with ice slurry before exertion in a hot environment reduced Tc during the first 30 minutes of the exercise bout. Exercise time and distance completed were not different between treatments. Skin temperature, heart rate, and perceptual responses rose in both conditions during exercise but did not differ by condition. CONCLUSION Pretreatment with ice slurry prior to exertion in wildland firefighting garments results in a modest reduction in Tc during the first 30 minutes of exercise when compared to pretreatment with control beverage but the ice slurry precooling advantage did not persist throughout the 45-minute exercise protocol.
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Precooling methods and their effects on athletic performance : a systematic review and practical applications. Sports Med 2013; 43:207-25. [PMID: 23329610 DOI: 10.1007/s40279-012-0014-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Precooling is a popular strategy used to combat the debilitating effects of heat-stress-induced fatigue and extend the period in which an individual can tolerate a heat-gaining environment. Interest in precooling prior to sporting activity has increased over the past three decades, with options including the application (external) and ingestion (internal) of cold modalities including air, water and/or ice, separately or in combination, immediately prior to exercise. Although many studies have observed improvements in exercise capacity or performance following precooling, some strategies are more logistically challenging than others, and thus are often impractical for use in competition or field settings. OBJECTIVE The purpose of this article was to comprehensively evaluate the established precooling literature, which addresses the application of cooling strategies that are likely to enhance field-based sports performance, while discussing the practical and logistical issues associated with these methods. We undertook a narrative examination that focused on the practical and event-specific application of precooling and its effect on physiological parameters and performance. DATA SOURCES Relevant precooling literature was located through the PubMed database with second- and third-order reference lists manually cross matched for relevant journal articles. The last day of the literature search was 31 January 2012. STUDY SELECTION Relevant studies were included on the basis of conforming to strict criteria, including the following: (i) cooling was conducted before exercise; (ii) cooling was conducted during the performance task in a manner that was potentially achievable during sports competition; (iii) a measure of athletic performance was assessed; (iv) subjects included were able bodied, and free of diseases or disorders that would affect thermoregulation; (v) subjects were endurance-trained humans (maximal oxygen uptake [[Formula: see text]O(2max)] >50 ml/kg/min for endurance protocols); (vi) cooling was not performed on already hyperthermic subjects that were in immediate danger of heat-related illnesses or had received passive heating treatments; (vii) drink ingestion protocols were used for the intended purpose of benefiting thermoregulation as a result of beverage temperature; and (viii) investigations employed ≥ six subjects. Initial searches yielded 161 studies, but 106 were discarded on failing to meet the established criteria. This final summary evaluated 74 precooling treatments, across 55 studies employing well trained subjects. STUDY APPRAISAL AND SYNTHESIS METHODS Key physiological and performance information from each study was extracted and presented, and includes respective subject characteristics, detailed precooling methods, exercise protocols, environmental conditions, along with physiological and performance outcomes. Data were presented in comparison to respective control treatments. For studies that include more than one treatment intervention, the comparative results between each precooling treatment were also presented. The practical benefits and limitations of employing each strategy in the field and in relation to sports performance were summarized. RESULTS Clear evidence of the benefits for a range of precooling strategies undertaken in the laboratory setting exists, which suggest that these strategies could be employed by athletes who compete in hot environmental conditions to improve exercise safety, reduce their perceived thermal stress and improve sports performance. LIMITATIONS This review did not include a systematic assessment of the study quality rating and provided a subjective assessment of the pooled outcomes of studies, which range in precooling methodologies and exercise outcomes. The wide range of research designs, precooling methods, environmental conditions and exercise protocols make it difficult to integrate all the available research into single findings. CONCLUSION Most laboratory studies have shown improvements in exercise performance following precooling and the emergence of strategies that are practically relevant to the field setting now allow scientists to individualize relevant strategies for teams and individuals at competition locations. Future research is warranted to investigate the effectiveness of practical precooling strategies in competition or field settings.
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Duffield R, Coutts A, McCall A, Burgess D. Pre-cooling for football training and competition in hot and humid conditions. Eur J Sport Sci 2013. [DOI: 10.1080/17461391.2011.589474] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Wegmann M, Faude O, Poppendieck W, Hecksteden A, Fröhlich M, Meyer T. Pre-cooling and sports performance: a meta-analytical review. Sports Med 2012; 42:545-64. [PMID: 22642829 DOI: 10.2165/11630550-000000000-00000] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Pre-cooling is used by many athletes for the purpose of reducing body temperature prior to exercise and, consequently, decreasing heat stress and improving performance. Although there are a considerable number of studies showing beneficial effects of pre-cooling, definite conclusions on the effectiveness of pre-cooling on performance cannot yet be drawn. Moreover, detailed analyses of the specific conditions under which pre-cooling may be most promising are, so far, missing. Therefore, we conducted a literature search and located 27 peer-reviewed randomized controlled trials, which addressed the effects of pre-cooling on performance. These studies were analysed with regard to performance effects and several test circumstances (environmental temperature, test protocol, cooling method, aerobic capacity of the subjects). Eighteen studies were performed in a hot (>26°C) environment and eight in a moderate. The cooling protocols were water application (n = 12), cooling packs (n = 3), cold drinks (n = 2), cooling vest (n = 6) and a cooled room (n = 4). The following different performance tests were used: short-term, high-intensity sprints (n = 2), intermittent sprints (n = 6), time trials (n = 10), open-end tests (n = 7) and graded exercise tests (n = 2). If possible, subjects were grouped into different aerobic capacity levels according to their maximal oxygen consumption (VO(2max)): medium 55-65 mL/kg/min (n = 11) and high >65 mL/kg/min (n = 6). For all studies the relative changes of performance due to pre-cooling compared with a control condition, as well as effect sizes (Hedges' g) were calculated. Mean values were weighted according to the number of subjects in each study. Pre-cooling had a larger effect on performance in hot (+6.6%, g = 0.62) than in moderate temperatures (+1.4%, g = 0.004). The largest performance enhancements were found for endurance tests like open-end tests (+8.6%, g = 0.52), graded exercise tests (+6.0%, g = 0.44) and time trials (+4.2%, g = 0.44). A similar effect was observed for intermittent sprints (+3.3%, g = 0.43), whereas performance changes were smaller during short-term, high-intensity sprints (-0.5%, g = 0.03). The most promising cooling methods were cold drinks (+15.0%, g = 1.68), cooling packs (+5.6%, g = 0.70) and a cooled room (+10.7%, g = 0.49), whereas a cooling vest (+4.8%, g = 0.31) and water application (+1.2%, g = 0.21) showed only small effects. With respect to aerobic capacity, the best results were found in the subjects with the highest VO(2max) (high +7.7%, g = 0.65; medium +3.8%, g = 0.27). There were four studies analysing endurance-trained athletes under time-trial conditions, which, in a practical sense, seem to be most relevant. Those studies found an average effect on performance of 3.7% (g = 0.48). In summary, pre-cooling can effectively enhance endurance performance, particularly in hot environments, whereas sprint exercise is barely affected. In particular, well trained athletes may benefit in a typical competition setting with practical and relevant effects. With respect to feasibility, cold drinks, cooling packs and cooling vests can be regarded as best-practice methods.
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Affiliation(s)
- Melissa Wegmann
- Saarland University, Institute of Sports and Preventive Medicine, Saarbrcken, Germany.
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Hausswirth C, Duffield R, Pournot H, Bieuzen F, Louis J, Brisswalter J, Castagna O. Postexercise cooling interventions and the effects on exercise-induced heat stress in a temperate environment. Appl Physiol Nutr Metab 2012; 37:965-75. [PMID: 22827512 DOI: 10.1139/h2012-077] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to examine the effects of cool water immersion (20 °C; CWI) while wearing a cooling jacket (Cryovest;V) and a passive control (PAS) as recovery methods on physiological and thermoregulatory responses between 2 exercise bouts in temperate conditions. Nine well-trained male cyclists performed 2 successive bouts of 45 min of endurance cycling exercise in a temperate environment (20 °C) separated by 25 min of the respective recovery interventions. Capillary blood samples were obtained to measure lactate (La⁻), sodium (Na⁺), bicarbonate (HCO₃⁻) concentrations and pH, whilst body mass loss (BML), core temperature (T(core)), skin temperature (T(skin)), heart rate (HR), oxygen uptake , and minute ventilation were measured before (Pre), immediately after the first exercise bout (Ex1), the recovery (R), and after the second exercise bout (Ex2). V and CWI both resulted in a reduction of T(skin) at R (-2.1 ± 0.01 °C and -11.6 ± 0.01 °C, respectively, p < 0.01). Despite no difference in final values post-Ex2 (p > 0.05), V attenuated the rise in HR, minute ventilation, and oxygen uptake from Ex1 to Ex2, while T(core) and T(skin) were significantly lower following the second session (p < 0.05). Further, CWI was also beneficial in lowering T(core), T(skin), and BML, while a rise in Na⁺ was observed following Ex2 (p < 0.05). Overall results indicate that cooling interventions (V and CWI) following exercise in a temperate environment provide a reduction in thermal strain during ensuing exercise bouts.
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Affiliation(s)
- Christophe Hausswirth
- National Institute of Sport, for Expertise and Performance, Research Department, Paris, France.
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Luomala MJ, Oksa J, Salmi JA, Linnamo V, Holmér I, Smolander J, Dugué B. Adding a cooling vest during cycling improves performance in warm and humid conditions. J Therm Biol 2012. [DOI: 10.1016/j.jtherbio.2011.10.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Skein M, Duffield R, Cannon J, Marino FE. Self-paced intermittent-sprint performance and pacing strategies following respective pre-cooling and heating. Eur J Appl Physiol 2011; 112:253-66. [PMID: 21537928 DOI: 10.1007/s00421-011-1972-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 04/15/2011] [Indexed: 11/28/2022]
Abstract
This study examined the effects of pre-exercise cooling and heating on neuromuscular function, pacing and intermittent-sprint performance in the heat. Ten male, team sport athletes completed three randomized, counterbalanced conditions including a thermo-neutral environment (CONT), whole body submersion in an ice bath (ICE) and passive heating in a hot environment (HEAT) before 50 min of intermittent-sprint exercise (ISE) in the heat (31 + 1°C). Exercise involved repeated 15 m maximal sprints and self-paced exercise of varying intensities. Performance was measured by sprint times and distance covered during self-paced exercise. Maximal isometric contractions were performed to determine the maximal voluntary torque (MVT), activation (VA) and contractile properties. Physiological measures included heart rate (HR), core (T (core)) and skin (T (skin)) temperatures, capillary blood and perceptual ratings. Mean sprint times were slower during ICE compared to HEAT (P < 0.05). Total distance covered was not different between conditions, but less distance was covered during HEAT in 31-40 min compared to CONT, and 41-50 min compared to ICE (P < 0.05). MVT was reduced post-exercise compared to post-intervention in CONT and HEAT. VA was reduced post-intervention in HEAT compared to CONT and ICE, and post-exercise compared to ICE (P < 0.05). HR, T (core) and T (skin) during exercise were lower in ICE compared to CONT and HEAT (P < 0.05). Sprint times and distance covered were not affected by ICE and HEAT conditions compared to CONT. However, initial sprint performance was slowed by pre-cooling, with improvements following passive heating possibly due to altered contractile properties. Conversely, pre-cooling improved exercise intensities, whilst HEAT resulted in greater declines in muscle recruitment and ensuing distance covered.
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Ranalli GF, Demartini JK, Casa DJ, McDermott BP, Armstrong LE, Maresh CM. Effect of body cooling on subsequent aerobic and anaerobic exercise performance: a systematic review. J Strength Cond Res 2011; 24:3488-96. [PMID: 21088554 DOI: 10.1519/jsc.0b013e3181fb3e15] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Body cooling has become common in athletics, with numerous studies looking at different cooling modalities and different types of exercise. A search of the literature revealed 14 studies that measured performance following cooling intervention and had acceptable protocols for exercise and performance measures. These studies were objectively analyzed with the Physiotherapy Evidence Database (PEDro) scale, and 13 of the studies were included in this review. These studies revealed that body cooling by various modalities had consistent and greater impact on aerobic exercise performance (mean increase in performance = 4.25%) compared to anaerobic (mean increase in performance = 0.66%). Different cooling modalities, and cooling during different points during an exercise protocol, had extremely varied results. In conclusion, body cooling seems to have a positive effect on aerobic performance, although the impact on anaerobic performance may vary and often does not provide the same positive effect.
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Affiliation(s)
- Gregory F Ranalli
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut, USA.
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DUFFIELD ROB, GREEN ROBBIE, CASTLE PAUL, MAXWELL NEIL. Precooling Can Prevent the Reduction of Self-Paced Exercise Intensity in the Heat. Med Sci Sports Exerc 2010; 42:577-84. [DOI: 10.1249/mss.0b013e3181b675da] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Price MJ, Boyd C, Goosey-Tolfrey VL. The physiological effects of pre-event and midevent cooling during intermittent running in the heat in elite female soccer players. Appl Physiol Nutr Metab 2010; 34:942-9. [PMID: 19935857 DOI: 10.1139/h09-078] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to examine the effects of both pre-exercise and combined pre-exercise and midexercise cooling strategies during simulated match play in elite female soccer players in the heat. Eight elite female soccer players performed two 45 min periods of intermittent running separated by 15 min seated rest on 3 separate occasions (30.6 +/- 0.2 degrees C, 63.4 +/- 2.5% relative humidity). Participants undertook a no-cooling (CON) or ice-vest cooling for 20 min pre-exercise (PRE) or both pre-exercise and during the 15 min rest period (PRE+MID). Rectal temperature (Tre), skin temperatures, and heart rate were monitored continuously. Mean skin temperature (TMS) and heat storage were calculated. Significant interactions (trial x time) were observed for the change in Tre from rest, TMS, and heat storage (p < 0.05). The change in Tre from rest was greater during CON when compared with PRE and PRE+MID from 35 min until the end of exercise (p < 0.05). When compared with CON (p < 0.05), TMS was lower after precooling (PRE and PRE+MID) and during the 15 min rest period and the first 5 min of the second exercise bout for PRE+MID. Heat storage was also lower after precooling (PRE and PRE+MID) (p < 0.05) and from 60 min until the end of exercise for PRE+MID (p < 0.05) and until 85 min and again at 95 min during PRE (p < 0.05). The results of this study suggest that both cooling strategies were effective in reducing thermal strain during intermittent exercise in the heat. However, PRE+MID cooling was more effective than PRE cooling in offsetting heat storage.
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Affiliation(s)
- Michael J Price
- Department of Biomolecular and Sports Science, Faculty of Health and Life Sciences, Coventry University, Priory Street, Coventry, UK
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Walker TB, Zupan MF, McGregor JN, Cantwell AR, Norris TD. Is Performance of Intermittent Intense Exercise Enhanced by Use of a Commercial Palm Cooling Device? J Strength Cond Res 2009; 23:2666-72. [DOI: 10.1519/jsc.0b013e3181b1f6a7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Duffield R, Steinbacher G, Fairchild TJ. The Use of Mixed-Method, Part-Body Pre-Cooling Procedures for Team-Sport Athletes Training in the Heat. J Strength Cond Res 2009; 23:2524-32. [DOI: 10.1519/jsc.0b013e3181bf7a4f] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Recovery of voluntary and evoked muscle performance following intermittent-sprint exercise in the heat. Int J Sports Physiol Perform 2009; 4:254-68. [PMID: 19567928 DOI: 10.1123/ijspp.4.2.254] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE This study investigated the effects of hot conditions on the acute recovery of voluntary and evoked muscle performance and physiological responses following intermittent exercise. METHODS Seven youth male and six female team-sport athletes performed two sessions separated by 7 d, involving a 30-min exercise protocol and 60-min passive recovery in either 22 degrees C or 33 degrees C and 40% relative humidity. The exercise protocol involved a 20-s maximal sprint every 5 min, separated by constant-intensity exercise at 100 W on a cycle ergometer. Maximal voluntary contraction (MVC) and a resting evoked twitch (Pf) of the right knee extensors were assessed before and immediately following exercise and again 15, 30, and 60 min postexercise, and capillary blood was obtained at the same time points to measure lactate, pH, and HCO3. During and following exercise, core temperature, heart rate and rating of perceived exertion (RPE) were also measured. RESULTS No differences (P=0.73 to 0.95) in peak power during repeated sprints were present between conditions. Postexercise MVC was reduced (P<.05) in both conditions and a moderate effect size (d=0.60) indicated a slower percentage MVC recovered by 60 min in the heat (83+/-10 vs 74+/-11% recovered). Both heart rate and core temperature were significantly higher (P<.05) during recovery in the heat. Capillary blood values did not differ between conditions at any time point, whereas sessional RPE was higher 60 min postexercise in the heat. CONCLUSIONS The current data suggests that passive recovery in warm temperatures not only delays cardiovascular and thermal recovery, but may also slow the recovery of MVC and RPE.
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Kostopoulos D, Rizopoulos K. Effect of topical aerosol skin refrigerant (Spray and Stretch technique) on passive and active stretching. J Bodyw Mov Ther 2008; 12:96-104. [DOI: 10.1016/j.jbmt.2007.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 11/22/2007] [Accepted: 11/23/2007] [Indexed: 11/15/2022]
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Duffield R, Marino FE. Effects of pre-cooling procedures on intermittent-sprint exercise performance in warm conditions. Eur J Appl Physiol 2007; 100:727-35. [PMID: 17476523 DOI: 10.1007/s00421-007-0468-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2007] [Indexed: 11/25/2022]
Abstract
The aim of this study was to determine whether pre-cooling procedures improve both maximal sprint and sub-maximal work during intermittent-sprint exercise. Nine male rugby players performed a familiarisation session and three testing sessions of a 2 x 30-min intermittent sprint protocol, which consisted of a 15-m sprint every min separated by free-paced hard-running, jogging and walking in 32 degrees C and 30% humidity. The three sessions included a control condition, Ice-vest condition and Ice-bath/Ice-vest condition, with respective cooling interventions imposed for 15-min pre-exercise and 10-min at half-time. Performance measures of sprint time and % decline and distance covered during sub-maximal exercise were recorded, while physiological measures of core temperature (T (core)), mean skin temperature (T (skin)), heart rate, heat storage, nude mass, rate of perceived exertion, rate of thermal comfort and capillary blood measures of lactate [La(-)], pH, Sodium (Na(+)) and Potassium (K(+)) were recorded. Results for exercise performance indicated no significant differences between conditions for the time or % decline in 15-m sprint efforts or the distance covered during sub-maximal work bouts; however, large effect size data indicated a greater distance covered during hard running following Ice-bath cooling. Further, lowered T (core), T (skin), heart rate, sweat loss and thermal comfort following Ice-bath cooling than Ice-vest or Control conditions were present, with no differences present in capillary blood measures of [La(-)], pH, K(+) or Na(+). As such, the ergogenic benefits of effective pre-cooling procedures in warm conditions for team-sports may be predominantly evident during sub-maximal bouts of exercise.
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Affiliation(s)
- Rob Duffield
- School of Human Movement, Charles Sturt University, Panorama Avenue, Bathurst, NSW 2795, Australia.
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Flouris AD, Cheung SS. Design and control optimization of microclimate liquid cooling systems underneath protective clothing. Ann Biomed Eng 2006; 34:359-72. [PMID: 16463083 DOI: 10.1007/s10439-005-9061-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Accepted: 09/27/2005] [Indexed: 10/25/2022]
Abstract
The use of protective clothing, whether in space suits, hazardous waste disposal, or sporting equipment, generally increases the risk of heat stress and hyperthermia by impairing the capacity for evaporative heat exchange from the body to the environment. To date the most efficient method of microclimate cooling underneath protective clothing has been via conductive heat exchange from circulating cooling fluid next to the skin. In order to make the use of liquid microclimate cooling systems ((LQ)MCSs) as portable and practical as possible, the physiological and biomedical engineering design goals should be towards maximizing the efficiency of cooling to maintain thermal comfort/neutrality with the least cooling possible to minimize coolant and power requirements. Meeting these conditions is an extremely complex task that requires designing for a plethora of different factors. The optimal fitting of the (LQ)MCSs, along with placement and design of tubing and control of cooling, appear to be key avenues towards maximizing efficiency of heat exchange. We review the history and major design constraints of (LQ)MCSs, the basic principles of human thermoregulation underneath protective clothing, and explore potential areas of research into tubing/fabric technology, coolant distribution, and control optimization that may enhance the efficiency of (LQ)MCSs.
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Affiliation(s)
- A D Flouris
- Environmental Ergonomics Laboratory, School of Health and Human Performance, Dalhousie University, 6230 South Street, Halifax, Nova Scotta, Canada
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Castle PC, Macdonald AL, Philp A, Webborn A, Watt PW, Maxwell NS. Precooling leg muscle improves intermittent sprint exercise performance in hot, humid conditions. J Appl Physiol (1985) 2005; 100:1377-84. [PMID: 16339344 DOI: 10.1152/japplphysiol.00822.2005] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We used three techniques of precooling to test the hypothesis that heat strain would be alleviated, muscle temperature (Tmu) would be reduced, and as a result there would be delayed decrements in peak power output (PPO) during exercise in hot, humid conditions. Twelve male team-sport players completed four cycling intermittent sprint protocols (CISP). Each CISP consisted of twenty 2-min periods, each including 10 s of passive rest, 5 s of maximal sprint against a resistance of 7.5% body mass, and 105 s of active recovery. The CISP, preceded by 20 min of no cooling (Control), precooling via an ice vest (Vest), cold water immersion (Water), and ice packs covering the upper legs (Packs), was performed in hot, humid conditions (mean +/- SE; 33.7 +/- 0.3 degrees C, 51.6 +/- 2.2% relative humidity) in a randomized order. The rate of heat strain increase during the CISP was faster in Control than Water and Packs (P < 0.01), but it was similar to Vest. Packs and Water blunted the rise of Tmu until minute 16 and for the duration of the CISP (40 min), respectively (P < 0.01). Reductions in PPO occurred from minute 32 onward in Control, and an increase in PPO by approximately 4% due to Packs was observed (main effect; P < 0.05). The method of precooling determined the extent to which heat strain was reduced during intermittent sprint cycling, with leg precooling offering the greater ergogenic effect on PPO than either upper body or whole body cooling.
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Affiliation(s)
- Paul C Castle
- Chelsea School Research Centre, University of Brighton, 30 Carlisle Rd., Eastbourne BN20 7SP, UK.
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