Strategies and factors associated with preparing for competing in the heat: a cohort study at the 2015 IAAF World Athletics Championships.
OBJECTIVE
Assess exertional heat illness (EHI) history and preparedness in athletes competing in a World Athletics Championships under hot/humid conditions and identify the factors associated with preparedness strategies.


METHODS
Of the 207 registered national teams invited to participate in the study, 50 (24%) accepted. The 957 athletes (49% of all 1965 registered) in these teams were invited to complete a precompetition questionnaire evaluating EHI history, heat stress prevention (heat acclimatisation, precooling and hydration) and recovery. Responses from 307 (32%) athletes were separated in field events, sprints, middle-distance and long-distance running, and decathlon/heptathlon for analysis.


RESULTS
48% of athletes had previously experienced EHI symptoms and 8.5% had been diagnosed with EHI. 15% heat acclimatised (∼20 days) before the championships. 52% had a precooling strategy, ice slurry ingestion (24%) being the most prevalent and women using it more frequently than men (p=0.005). 96% of athletes had a fluid consumption strategy, which differed between event categories (p<0.001). The most common volumes planned on being consumed were 0.5-1 L (27.2%) and ≥2 L (21.8%), water being the most frequent. 89% of athletes planned on using at least one recovery strategy. Female sex (p=0.024) and a previous EHI diagnosis increased the likelihood of using all 3 prevention strategies (p<0.001).


CONCLUSIONS
At a World Championships with expected hot/humid conditions, less than one-fifth of athletes heat acclimatised, half had a precooling strategy and almost all a hydration plan. Women, and especially athletes with an EHI history, were more predisposed to use a complete heat stress prevention strategy. More information regarding heat acclimatisation should be provided to protect athlete health and optimise performance at major athletics competitions in the heat.
Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Julien D
JD
Périard
Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Sébastien
S
Racinais
Athletics Research Center, Linköping University, Linköping, Sweden.
Toomas
http://orcid.org/0000-0001-6049-5402
T
Timpka
Athletics Research Center, Linköping University, Linköping, Sweden.
Örjan
Ö
Dahlström
Athletics Research Center, Linköping University, Linköping, Sweden.
Armin
A
Spreco
Athletics Research Center, Linköping University, Linköping, Sweden.|Swedish Athletics Association, Stockholm, Sweden.
Jenny
http://orcid.org/0000-0002-1551-1722
J
Jacobsson
Athletics Research Center, Linköping University, Linköping, Sweden.|Department of Orthopaedics and Rehabilitation, Moi University, Eldoret, Kenya.
Victor
V
Bargoria
Athletics Research Center, Linköping University, Linköping, Sweden.|Young Adults Centre, Region Östergötland, Linköping, Sweden.
Karin
K
Halje
Sports Medicine Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Juan-Manuel
JM
Alonso
D000064:Acclimatization / Q000502:physiology*; D056352:Athletes; D001831:Body Temperature; D015331:Cohort Studies; D004327:Drinking Behavior; D005260:Female; D018882:Heat Stress Disorders / Q000517:prevention & control*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D012420:Running / Q000502:physiology*; D011795:Surveys and Questionnaires; D014142:Track and Field / Q000502:physiology
Elite performance; Exertional heat stress; Heat acclimatisation; Hydration