Author(s): NAITO, T., HAYASHI, S., OHHASHI, M., NAKAMURA, M., Institution: HOKKAI-GAKUEN UNIVERSITY, Country: JAPAN, Abstract-ID: 668

INTRODUCTION:
Tennis is often held in hot outdoor environments, which the high solar radiation and ambient temperature impose an additional stress on players and resulting in high core and skin temperatures. Therefore, to prevent the development of hyperthermia, combined cooling by both internal and external cooling may be more effective strategy than the conventionally used internal cooling alone. The purpose of this study was to investigate the effect of combined cooling during break times in simulated match-play tennis in hot outdoor environments.
METHODS:
Eight healthy males (age: 21 ± 2 years, height: 170.8 ± 4.1 cm, body mass: 63.84 ± 3.84 kg) performed two trials in outside (ambient temperature: 32.3 ± 0.6℃, relative humidity: 60.2 ± 3.4%, solar radiation: 921 ± 108 W/m2), each time completing 4 sets of simulated match-play. During International Tennis Federation-mandated breaks (90-s between odd-numbered games; 120-s between sets), either ice slurry ingestion (INT) or ice slurry ingestion + wearing fan cooling jacket (COM) were conducted. The estimates core temperature, mean skin temperature, heart rate, rating of thermal sensation, comfort, and perceived exertion and total sweat loss were measured.
RESULTS:
In each trial, the different one participant did not complete the COM (up to 4 sets 3 games) or INT (up to 4 sets 1 game) trials. There were no significant differences in estimates core temperature, mean skin temperature, heart rate, and total sweat loss between trials. Rating of thermal sensation and comfort were significantly lower in the COM trial than that in the INT trial.
CONCLUSION:
The results of this study showed that the combined cooling by internal and external cooling did not change the physiological strain compared with internal cooling alone, although perceptual sensation was improved by combined cooling. Therefore, in order to reduce the physiological strain, it is necessary to consider the more powerful external cooling garments in addition to ice slurry ingestion.