Medical Training in Belgrade for the World Athletics Cross Country Championships
The health of athletes facing heat-related risks is a major concern for International Federations (IFs). To assess the danger of heat and protect athletes, most IFs rely on thermal indices. Thermal indices are quantitative indicators allowing to assess the environmental impact on individuals. A recent study on this topic has been published in the British Journal of Sport Medicine here.
The study was authored by David Bandiera, a PhD student in sport sciences at the University of Rome "Foro Italico," in collaboration with the Health & Science department at World Athletics.
The main result of this study shows that among the 45 sports represented at Paris 2024 Olympics Games, 33% have been identified as having high, very high, or extreme risk of heat stress (e.g. athletics, triathlon, road cycling). Most of the sports at risk are using a thermal index called Wet Bulb Globe Temperature (WBGT) (e.g. athletics, tennis, football).
The WBGT measures heat stress in direct sunlight by considering temperature, humidity, wind speed, sun angle, and cloud cover. It was developed in the 1950s by the US Army and Marine Corps after several heat-related casualties in training camps. IFs using this index have defined thresholds corresponding to different level of risk and mitigation strategies.
On another hand, some IFs base their decisions on the measurement of the air temperature and the relative humidity (e.g. hockey, modern pentathlon) while others do not mention the measurement of the environmental conditions.
For sports at risk of heat stress, it is essential to objectively evaluate environmental conditions to prevent potentially fatal outcomes due to the heat. This can be achieved by using or developing thermal indices that are specifically tailored to the world of sport, and not derived from the general population or the military. David Bandiera insists on this publication that “thermal indices currently used do not completely represent the thermal strain endured by athletes”. Indeed, this overlooks critical factors such as the significant metabolic heat production of athletes and their varying levels of acclimation.
After the measurement of the heat stress, IFs apply different mitigation strategies to reduce the risk of exertional heat illness. For example, events are often scheduled during cooler morning or evening hours (e.g. athletics, triathlon, rowing) and periods of rest are increased for intermittent sports (e.g. hockey, football, tennis). For continuous activities, additional hydration stations (e.g. athletics, triathlon, cycling) or reducing course distance (e.g. triathlon, equestrian) can be implemented. On-site, providing cool areas is recommended by most IFs, including air-conditioned rooms or tents for shade, along with the supply of ice, cold drinks, water-soaked towels, and fans. As a last resort, when heat stress is too critical, IFs may decide to cancel and reschedule the event (e.g. triathlon, marathon swimming, tennis).
To summarize, for sports at risk of heat stress, the three following steps are recommended to protect athletes' health:
- Chose and validate thermal indices that objectively represent the thermal strain of athletes in the specific activity
- Define mitigation strategies accordingly to reduce the risks
- Adequately monitor and diagnose the number of athletes suffering from exertional heat stroke illnesses or heat strokes during competitions
