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Hydration and cooling in elite athletes: relationship with performance, body mass loss and body temperatures during the Doha 2019 IAAF World Athletics Championships
  1. Sebastien Racinais1,
  2. Mohammed Ihsan1,2,
  3. Lee Taylor3,4,
  4. Marco Cardinale1,5,
  5. Paolo Emilio Adami6,
  6. Juan Manuel Alonso7,
  7. Nicolas Bouscaren8,
  8. Sebastian Buitrago9,
  9. Chris J Esh1,3,
  10. Josu Gomez-Ezeiza10,
  11. Frederic Garrandes6,
  12. George Havenith11,
  13. Mariem Labidi1,
  14. Gunter Lange6,
  15. Alexander Lloyd11,
  16. Sebastien Moussay12,
  17. Khouloud Mtibaa13,
  18. Nathan Townsend1,14,
  19. Mathew G Wilson1,5,
  20. Stephane Bermon6,15
  1. 1Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
  2. 2Human Potential Translational Research Program, NUS Yong Loo Lin School of Medicine, Singapore
  3. 3School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
  4. 4Human Performance Research Centre, University of Technology Sydney, Sydney, New South Wales, Australia
  5. 5Institute of Sport Exercise and Health (ISEH), University College London, London, UK
  6. 6Health and Science Department, World Athletics, Monaco
  7. 7Sports Medicine, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
  8. 8Inserm CIC1410, CHU Reunion, La Réunion, France
  9. 9Olympic Training and Service Centre Lower Saxony, Hannover, Germany
  10. 10Institute of Sport and Exercise Medicine, Stellenbosch University Faculty of Medicine and Health Sciences, Cape Town, Western Cape, South Africa
  11. 11Environmental Ergonomics Research Centre, Loughborough University, Loughborough, Leics, UK
  12. 12Normandie Univ, UNICAEN, INSERM, COMETE, CYCERON, CHU Caen, Caen, Normandie, France
  13. 13Physical Education Department, College of Education, Qatar University, Doha, Qatar
  14. 14College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Ad Dawhah, Qatar
  15. 15Human Motricity Laboratory Expertise Sport Health, Cote d'Azur University, Nice, Provence-Alpes-Côte d'Azu, France
  1. Correspondence to Dr Sebastien Racinais, Research and Scientific Support, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, PO Box 29222, Qatar; sebastien.racinais{at}aspetar.com

Abstract

Purpose To characterise hydration, cooling, body mass loss, and core (Tcore) and skin (Tsk) temperatures during World Athletics Championships in hot-humid conditions.

Methods Marathon and race-walk (20 km and 50 km) athletes (n=83, 36 women) completed a pre-race questionnaire. Pre-race and post-race body weight (n=74), Tcore (n=56) and Tsk (n=49; thermography) were measured.

Results Most athletes (93%) had a pre-planned drinking strategy (electrolytes (83%), carbohydrates (81%)) while ice slurry was less common (11%; p<0.001). More men than women relied on electrolytes and carbohydrates (91%–93% vs 67%–72%, p≤0.029). Drinking strategies were based on personal experience (91%) rather than external sources (p<0.001). Most athletes (80%) planned pre-cooling (ice vests (53%), cold towels (45%), neck collars (21%) and ice slurry (21%)) and/or mid-cooling (93%; head/face dousing (65%) and cold water ingestion (52%)). Menthol usage was negligible (1%–2%). Pre-race Tcore was lower in athletes using ice vests (37.5°C±0.4°C vs 37.8°C±0.3°C, p=0.024). Tcore (pre-race 37.7°C±0.3°C, post-race 39.6°C±0.6°C) was independent of event, ranking or performance (p≥0.225). Pre-race Tsk was correlated with faster race completion (r=0.32, p=0.046) and was higher in non-finishers (did not finish (DNF); 33.8°C±0.9°C vs 32.6°C±1.4°C, p=0.017). Body mass loss was higher in men than women (−2.8±1.5% vs −1.3±1.6%, p<0.001), although not associated with performance.

Conclusion Most athletes’ hydration strategies were pre-planned based on personal experience. Ice vests were the most adopted pre-cooling strategy and the only one minimising Tcore, suggesting that event organisers should be cognisant of logistics (ie, freezers). Dehydration was moderate and unrelated to performance. Pre-race Tsk was related to performance and DNF, suggesting that Tsk modulation should be incorporated into pre-race strategies.

  • thermoregulation
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Footnotes

  • Twitter @ephysiol, @Ihsan_mo, @Marco_Cardinale, @paolo_emilio, @DrJuanMAlonso, @goipergormance, @DrNathanT

  • Contributors SR designed the study. All authors contributed to data collection and data analyses. All authors revised the manuscript and approved the final version.

  • Funding This study was supported by World Athletics (formerly International Association of Athletics Federations, IAAF).

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval The project was approved by the Anti-Doping Laboratory Qatar ethics committee (E2019000302). All procedures complied with the Declaration of Helsinki and written informed consent was obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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