Optimal cooling strategies for players in Australian Tennis Open conditions

Abstract

Objectives: We compared the utility of four cooling interventions for reducing heat strain during simulated tennis match-play in an environment representative of the peak conditions possible at the Australian Open (45 °C, <10% RH, 475 W/m2 solar radiation). Design: Nine trained males undertook four trials in a climate chamber, each time completing 4 sets of simulated match-play. Methods: During ITF-mandated breaks (90-s between odd-numbered games; 120-s between sets), either iced towels (ICE), an electric fan (FANdry), a fan with moisture applied to the skin (FANwet), or ad libitum 10 °C water ingestion only (CON) was administered. Rectal temperature (Tre), mean skin temperature (Tsk), heart rate (HR), thermal sensation (TS), perceived exertion (RPE) and whole body sweating (WBSR) were measured. Results: After set 3, Tre was lower in ICE (38.2 ± 0.3 °C) compared to FANdry (38.7 ± 0.5 °C; p = 0.02) and CON (38.5 ± 0.5 °C; p = 0.05), while Tre in FANwet (38.2 ± 0.3 °C) was lower than FANdry (p = 0.05). End-exercise Tre was lower in ICE (38.1 ± 0.3 °C) and FANwet (38.2 ± 0.4 °C) than FANdry (38.9 ± 0.7 °C; p < 0.04) and CON (38.8 ± 0.5 °C; p < 0.04). Tsk for ICE (35.3 ± 0.8 °C) was lower than all conditions, and Tsk for FANwet (36.6 ± 1.1 °C) was lower than FANdry (38.1 ± 1.3 °C; p < 0.05). TS for ICE and FANwet were lower than CON and FANdry (p < 0.05). HR was suppressed in ICE and FANwet relative to CON and FANdry (p < 0.05). WBSR was greater in FANdry compared to FANwet (p < 0.01) and ICE (p < 0.001). Conclusions: Fan use must be used with skin wetting to be effective in hot/dry conditions. This strategy and the currently recommended ICE intervention both reduced Tre by ∼0.5–0.6 °C and Tsk by ∼1.0–1.5 °C while mitigating rises in HR and TS.