Thermoregulatory Responses, Athlete Preparation And Knowledge Of Elite Open Water Swimming Competition In Divergent Environments.

Elite open water swimming (OWS) competitions are conducted in various water temperatures (Tw; limits: 16-31 °C) thus presenting hypo- and hyper-thermic risk [Modest deviations (± 0.5-2 °C) in core temperature (Tc) have proven fatal]. The thermodynamic properties of water and blunted evaporative heat exchange exacerbate Tw derived challenges to ‘safe’ body temperature management and optimal performance. Despite OWS specific risk, limited: (i) Tc data in competition-relevant Tw’s; and (ii) knowledge of real-world and athlete adopted thermoregulatory aligned preparations for competition, are seen. PURPOSE: Characterise elite OWS Tc responses (ingestible telemetric pill), preparation, and aligned competition knowledge (via survey) to evidence-inform future thermoregulatory focused strategies to protect athlete health/performance. METHODS: In-race Tc was measured (n = 19; 13 male, 19.6 ± 2.6 yrs) at the LEN Open Water Cup (4th Leg; 18.2 °C, COLD) or the LEN Junior European OWS Championships (25.5 °C, WARM). Online survey also completed. RESULTS: Divergent individual Tc responses were seen (e.g., marked reductions and increases) within COLD/WARM (see Table 1 for central tendencies and dispersions). 33.3% (WARM) and 14.3% (COLD) trained in OWS settings ≤6 months annually with 58.3% (WARM) and 71.4% (COLD) using OWS settings only in summer months. 85.7% of (WARM) compared to 50% of (COLD) swimmers knew the predicted Tw for competition. 22.2% (WARM) used heat acclimation/acclimatisation (HA) strategies pre-competition. Of those who adopted HA in WARM, 11.1% suffered from negative symptomology related to body temperature in-race, compared to 33.3% who did not HA. CONCLUSION: Divergent Tc responses were evident within both COLD/WARM races. HA appears to offer some protection against undesired body temperature related symptomology. Therefore, individualised thermoregulatory competition practises are required alongside germane educational initiatives. Table 1: - Central Tendency and Dispersion of Race Tc Warm Event (n = 12, 9 male) Cold Event (n = 7, 4 male) Mean Race Tc (min-max) 38.1 °C (36.7 - 39.0 °C) 37.6 °C (35.5 - 38.7 °C) Mean Maximum Tc (min-max) 38.9 °C (38.2 - 39.5 °C) 38.4 °C (37.5 - 39.0 °C) Mean Minimum Tc (min-max) 37.2 °C (35.8-38.1 °C) 36.9 °C (35.0 - 37.9 °C) This project was funded by LEN European Aquatics.