ABSTRACT

　In open water swimming （OWS） in cold water （water temperature:16-18 ℃），swimmers are allowed to wear a wetsuit. Given that wetsuits retain heat, the wearing a wetsuit during OWS in cold water is considered to have a significant effect on the swimmer's body core temperature and thermal sensation. However, it is unclear how wearing a wetsuit affects body core temperature during OWS in cold water. Therefore, in the present study, we examined （1） the local skin thermal sensitivity of OWS swimmers, and （2） the effect wetsuit on body core temperature during OWS in cold water. In experiment 1, local skin warm and cool sensitivities were measured in 8 OWS swimmers（OWS group） and 15 healthy adults（Control group）．Although local skin warm sensitivity did not differ between groups, the OWS group tended to be less coldsensitive than the Control group （P = 0.075）．In experiment 2, four OWS swimmers performed two 2-hour OWS trials in cold water （water temperature:15-16℃） with （wetsuit trial） and without wetsuits （swimsuit trial）．Body core temperature was measured during OWS by ingestible thermometer. Body core temperature during OWS was higher in wetsuit trial than swimsuit trial（P = 0.046）．These results suggest that OWS swimmers tend to be more tolerant of cold than non-swimmers. In addition, wearing a wetsuit can prevent decrease in body core temperature during OWS in cold water.

DECENTE SPORTS SCIENCE Vol.46/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE