301
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Casadio JR, Kilding AE, Siegel R, Cotter JD, Laursen PB. Periodizing heat acclimation in elite Laser sailors preparing for a world championship event in hot conditions. Temperature (Austin) 2016; 3:437-443. [PMID: 28349083 PMCID: PMC5079264 DOI: 10.1080/23328940.2016.1184367] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/21/2016] [Accepted: 04/23/2016] [Indexed: 11/09/2022] Open
Abstract
Purpose: To examine the retention and re-acclimation responses during a periodized heat acclimation (HA) protocol in elite sailors preparing for the 2013 World Championships in Muscat, Oman (∼27–30°C, 40–60% RH). Methods: Two elite male Laser class sailors completed 5 consecutive days of HA (60 min per day in 35°C, 60% RH). Heat response tests (HRT) were performed on day 1 and 5 of HA, then 1 (decay 1, D1) and 2 (D2) weeks following HA. Participants were then re-acclimated (RA) for 2 days, within the next week, before a final HRT ∼72 h post-RA. Rectal temperature, plasma volume, heart rate, sweat rate, as well as thermal discomfort and rating of perceived exertion were measured during each HRT. Results: Rectal temperature decreased with HA (0.46 ± 0.05°C), while individual responses following D1, D2 and RA varied. Heart rate (14 ± 7 bpm), thermal discomfort (0.6 ± 0.1 AU) and rating of perceived exertion (1.8 ± 0.6 AU) decreased across HA, and adaptations were retained by D2. Plasma volume steadily increased over the decay period (D2 = 8.0 ± 1.3%) and after RA (15.5 ± 1.1%) compared with baseline. RA resulted in further thermoregulatory improvements in each Athlete, although individual adjustments varied. Conclusion: Heat strain was reduced in elite Laser sailors following HA and most thermoregulatory adaptations were retained for 2 weeks afterwards. RA may ‘top up’ adaptations after 2 weeks of HA decay.
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Affiliation(s)
- Julia R Casadio
- Sports Performance Research Institute New Zealand (SPRINZ), School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand; High Performance Sport New Zealand, Auckland, New Zealand
| | | | | | - James D Cotter
- School of Physical Education, Sport and Exercise Sciences, University of Otago , Dunedin, New Zealand
| | - Paul B Laursen
- Sports Performance Research Institute New Zealand (SPRINZ), School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand; High Performance Sport New Zealand, Auckland, New Zealand
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302
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Tyler CJ, Reeve T, Hodges GJ, Cheung SS. The Effects of Heat Adaptation on Physiology, Perception and Exercise Performance in the Heat: A Meta-Analysis. Sports Med 2016; 46:1699-1724. [DOI: 10.1007/s40279-016-0538-5] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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303
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Pokora I, Żebrowska A. Application of A Physiological Strain Index in Evaluating Responses to Exercise Stress - A Comparison Between Endurance and High Intensity Intermittent Trained Athletes. J Hum Kinet 2016; 50:103-114. [PMID: 28149347 PMCID: PMC5260640 DOI: 10.1515/hukin-2015-0142] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2016] [Indexed: 11/22/2022] Open
Abstract
The study evaluated differences in response to exercise stress between endurance and
high-intensity intermittent trained athletes in a thermoneutral environment using a
physiological strain index (PSI). Thirty-two subjects participated in a running
exercise under normal (23°C, 50% RH) conditions. The group included nine
endurance trained athletes (middle-distance runners - MD), twelve high-intensity
intermittent trained athletes (soccer players - HIIT) and eleven students who
constituted a control group. The exercise started at a speed of 4
km·h–1 which was increased every 3 min by 2
km·h–1 to volitional exhaustion. The heart rate was
recorded with a heart rate monitor and aural canal temperature was measured using an
aural canal temperature probe. The physiological strain index (PSI) and the
contribution of the circulatory and thermal components to the overall physiological
strain were calculated from the heart rate and aural canal temperature. The
physiological strain index differed between the study and control participants, but
not between the MD and HIIT groups. The physiological strain in response to exercise
stress in a thermoneutral environment was mainly determined based on the circulatory
strain (MD group - 73%, HIIT group – 70%). The contribution of the circulatory
and thermal components to the physiological strain did not differ significantly
between the trained groups (MD and HIIT) despite important differences in
morphological characteristics and training-induced systemic cardiovascular and
thermoregulatory adaptations.
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Affiliation(s)
- Ilona Pokora
- Department of Physiology, the Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
| | - Aleksandra Żebrowska
- Department of Physiology, the Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
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304
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Cardiovascular adaptations supporting human exercise-heat acclimation. Auton Neurosci 2016; 196:52-62. [DOI: 10.1016/j.autneu.2016.02.002] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 01/29/2016] [Accepted: 02/04/2016] [Indexed: 11/22/2022]
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305
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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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306
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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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307
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Karlsen A, Nybo L, Nørgaard SJ, Jensen MV, Bonne T, Racinais S. Time course of natural heat acclimatization in well-trained cyclists during a 2-week training camp in the heat. Scand J Med Sci Sports 2016; 25 Suppl 1:240-9. [PMID: 25943675 DOI: 10.1111/sms.12449] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2015] [Indexed: 11/29/2022]
Abstract
The aim of this study was to determine the time course of physiological adaptations and their relationship with performance improvements during 2 weeks of heat acclimatization. Nine trained cyclists completed 2 weeks of training in naturally hot environment (34 ± 3 °C; 18 ± 5% relative humidity). On days 1, 6, and 13, they performed standardized heat response tests (HRT-1, 2, 3), and 43.4-km time trials in the heat (TTH-1, 2, 3) were completed on days 2, 7, and 14. Within the first 5-6 days, sweat sodium concentration decreased from 75 ± 22 mmol/L to 52 ± 24 mmol/L, sweat rate increased (+20 ± 15%), and resting hematocrit decreased (-5.6 ± 5.4%), with no further changes during the remaining period. In contrast, power output during TTHs gradually improved from TTH-1 to TTH-2 (+11 ± 8%), and from TTH-2 to TTH-3 (+5 ± 4%). Individual improvements in performance from TTH-1 to TTH-2 correlated with individual changes in hematocrit (assessed after the corresponding HRT; r = -0.79, P < 0.05), however, were not related to changes in performance from TTH-2 to TTH-3. In trained athletes, sudomotor and hematological adaptations occurred within 5-6 days of training, whereas the additional improvement in performance after the entire acclimatization period did not relate to changes in these parameters.
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Affiliation(s)
- A Karlsen
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic Sports Medicine Hospital, Doha, Qatar; Department of Nutrition, Exercise and Sport Sciences, Section of Human Physiology, University of Copenhagen, Copenhagen, Denmark
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308
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Minson CT, Cotter JD. CrossTalk proposal: Heat acclimatization does improve performance in a cool condition. J Physiol 2015; 594:241-3. [PMID: 26668072 DOI: 10.1113/jp270879] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/22/2015] [Indexed: 11/08/2022] Open
Abstract
We believe available data support the thesis that HA can improve performance in cool conditions, and perhaps with less expense and fewer side-effects than hypoxia (Dempsey & Morgan, 2015), but its utility is unresolved and may be modest or absent in some settings and individuals. A few key issues are becoming clear, however. First, HA must be of sufficient stimulus and duration, with key evidence indicating longer is better. Second, individual variability in response to HA as an ergogenic aid needs to be considered. Third, key training aspects such as speed and intensity may need to be maintained, and ideally performed in a cooler environment to maximize gains and minimize fatigue (including the effects of matched absolute versus relative work rates on adaptations). Alternatively, passive heating should be considered (e.g. immediately after training). Fourth, there is no evidence that HA impairs cool weather performance, and thus HA is a useful strategy when the competitive environmental conditions are potentially hot or unknown. Fifth, much remains unknown about ideal timing for competition following HA and its decay. Lastly, an ergogenic effect of HA has yet to be studied in truly elite athletes.
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Affiliation(s)
| | - James D Cotter
- School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand
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309
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Neal RA, Corbett J, Massey HC, Tipton MJ. Effect of short-term heat acclimation with permissive dehydration on thermoregulation and temperate exercise performance. Scand J Med Sci Sports 2015. [DOI: 10.1111/sms.12526] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- R. A. Neal
- Department of Sport and Exercise Sciences; University of Portsmouth; Portsmouth UK
| | - J. Corbett
- Department of Sport and Exercise Sciences; University of Portsmouth; Portsmouth UK
| | - H. C. Massey
- Department of Sport and Exercise Sciences; University of Portsmouth; Portsmouth UK
| | - M. J. Tipton
- Department of Sport and Exercise Sciences; University of Portsmouth; Portsmouth UK
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310
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White AC, Salgado RM, Astorino TA, Loeppky JA, Schneider SM, McCormick JJ, McLain TA, Kravitz L, Mermier CM. The effect of 10 days of heat acclimation on exercise performance in acute hypobaric hypoxia (4350 m). Temperature (Austin) 2015; 3:176-85. [PMID: 27227084 PMCID: PMC4861181 DOI: 10.1080/23328940.2015.1072659] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 07/08/2015] [Indexed: 01/09/2023] Open
Abstract
To examine the effect (“cross-tolerance”) of heat acclimation (HA) on exercise performance upon exposure to acute hypobaric hypoxia (4350 m). Eight male cyclists residing at 1600 m performed tests of maximal aerobic capacity (VO2max) at 1600 m and 4350 m, a 16 km time-trial at 4350 m, and a heat tolerance test at 1600 m before and after 10 d HA at 40°C, 20% RH. Resting blood samples were obtained pre-and post- HA to estimate changes in plasma volume (ΔPV). Successful HA was indicated by significantly lower exercise heart rate and rectal temperature on day 10 vs. day 1 of HA and during the heat tolerance tests. Heat acclimation caused a 1.9% ΔPV, however VO2max was not significantly different at 1600 m or 4350 m. Time-trial cycling performance improved 28 sec after HA (p = 0.07), suggesting a possible benefit for exercise performance at acute altitude and that cross-tolerance between these variables may exist in humans. These findings do not clearly support the use of HA to improve exercise capacity and performance upon acute hypobaric hypoxia, however they do indicate that HA is not detrimental to either exercise capacity or performance.
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Affiliation(s)
- Ailish C White
- Department of Kinesiology, Point Loma Nazarene University, San Diego, CA, USA; Department of Health, Exercise, and Sports Sciences, University of New Mexico, Albuquerque, NM, USA
| | - Roy M Salgado
- Department of Health, Exercise, and Sports Sciences, University of New Mexico, Albuquerque, NM, USA; Department of Kinesiology, Occidental College, Los Angeles, CA, USA
| | - Todd A Astorino
- Department of Kinesiology, California State University San Marcos , San Marcos, CA, USA
| | - Jack A Loeppky
- Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
| | - Suzanne M Schneider
- Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
| | - James J McCormick
- Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
| | - Trisha A McLain
- Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
| | - Len Kravitz
- Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
| | - Christine M Mermier
- Department of Health, Exercise, and Sports Sciences, University of New Mexico , Albuquerque, NM, USA
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311
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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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312
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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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