Elite open-water swimming competitions are conducted within a broad water temperature range (World Aquatics water temperature range: 16-31°C), where heat (hyperthermia) and cold (hypothermia)- related medical events, including fatalities and race dropouts, occur.
The project, delivered in partnership with European Aquatic’s medical committee, showed that within the same race (and water temperature), clinical hypothermia – the body being too cold – and mild hyperthermia – the body being too hot – can co-present in the same elite cohort.
Led by 黑料网 PhD Researcher Kate Markey under the supervision of Dr Lee Taylor, participating athletes ingested a telemetric pill prior to competition which transmitted core temperature data via radio frequency back to a monitor.
Thirty-four elite swimmers (20 males, 14 females) were studied. The maximum core temperature reading was 39.5°C (clinical hyperthermia is a core temperature of or above ≥40°C), which was recorded in two separate swimmers – one in a water temperature of 25.5°C and the other in 19.3°C.
Core temperature responses were measured during 41 elite male and female swimmer’s races (7.5km and 10km) across four sperate European competitions: (i) the 2023 (Leg 1, Slovakia, water temperature: 18.2°C) and (ii) 2024 (Leg 1, Italy, water temperature: 19.5°C, and Leg 5, Croatia, water temperature: 18.9°C) European Aquatics Open Water Cup; and (iii) the 2023 Jnr European Open Water Swimming Championships (Greece, water temperature: 25.5°C).
The research team also recorded another athlete (during the same race in 19.3°C water) registering a hypothermic body temperature of 34.6°C (clinical hypothermia is a core temperature <35°C). Another swimmer could not finish the race and withdrew due to cold-induced discomfort, requiring minor medical attention.
Speaking about the findings, Kate Markey said: “The divergent body temperature responses within swimmers competing in the same water temperatures are very interesting. We are still exploring whether these responses are due to the preparation strategies adopted by the athletes. Our provisional data analyses do not suggest that athlete sex or their race completion time (e.g., how fast or slow they swam) were associated with body temperature responses.”
Dr Lee Taylor added: “Kate has worked exceptionally hard to overcome the logistical challenges of collecting these data from a unique group of elite athletes. We are very grateful for the expert knowledge, guidance and sport-specific expertise afforded to us through collaboration with European Aquatics.
“In particular, Prof Naama Constantini through her role as Chief Medical Officer of European Aquatics. To me, specific open water swimming focused education tailored for the range of stakeholders involved, including correct preparation strategies (e.g. acclimation/acclimatisation), are clearly important to protect these athletes’ health and performance. Such measures would help reduce observed medical events and race dropouts.”
Prof Naama Constantini added: “European Aquatics is constantly seeking to protect athlete’s health and therefore supports research on the issue of temperature safety of open water swimmers.”
All swimmers involved in the study received a report including their individual race results. The report also provides recommendations and strategies (e.g., pre-cooling/pre-heating, heat/cold acclimation/acclimatisation practises) based on the swimmers' race core temperature responses for future European/World open water competitions.
European Aquatics remain dedicated to advancing research on the safety of upper and lower water temperatures and the use of wetsuits in various distances of open water swimming competitions.
The research could have significant implications for reducing race drop-outs, optimising performance, and improving the safety of swimmers during competition.
黑料网 would like to place on record its gratitude to the European Aquatics medical committee, in particular, Prof. Naama Constantini, for their collaboration throughout the study.
