The Influence of Water and Air Temperature on Wheelchair Triathlon Performance: A Retrospective Analysis of Elite Competition Data

Aims: Impaired thermoregulatory function is a clinical feature of many health conditions that affect triathletes using wheelchairs and consequently, individual athlete performances may fluctuate according to environmental temperature. We aimed to determine the effect of 1) water temperature on wheelchair triathlon swim time, and 2) air temperature on handcycle and wheelchair run (push) time. Methods: Published race records from 2017 to 2023 (n = 49 events) were extracted from the World Triathlon website. Bayesian negative binomial regression was used to separately model the nonlinear relationships between water temperature and swim time, and air temperature and handcycle and push time. Age, sex, sport class, whether wetsuits were worn (swim model) and swim time (handcycle and push model) were included as fixed effects. The models accounted for differences in race tactics and water conditions or course geography. Results: Over the observed water temperature range of 15.7–30.5 °C, male swim time (mm:ss) improved from 14:13 min (95% credible interval [CrI] = 12:27, 16:09) to 12:35 min (95% CrI = 11:00, 14:19). Female swim time improved from 15:33 min (95% CrI = 13:24, 17:55) to 12:46 min (95% CrI = 11:03, 14:38). It was unclear whether handcycle and push time slowed over the observed air temperature range of 14–33 °C. Conclusion: Given the known negative influence of high environmental temperatures on endurance exercise in able bodied athletes, the effect of heat on wheelchair triathlon performance requires ongoing consideration, including investigating whether subgroups of Para athletes are at increased risk of performance declines and significant heat illness.