水分摂取間隔の違いが暑熱下運動中の体温調節反応に与える影響

EFFECTS OF WATER INGESTION INTERVAL ON THERMOREGULATORY RESPONSES DURING EXERCISE IN A HOT, HUMID ENVIRONMENT

Takatori Tadashi

Hasegawa Hiroshi

Yamasaki Masahiro

Komura Takashi

体力科学 : Japanese Journal of Physical Fitness and Sports Medicine

During exercise at high temperatures, body temperature increases, impairing exercise performance and resulting in heat illnesses. Water ingestion during exercise is a simple and practical strategy to prevent hyperthermia. In the present study, we examined the effects of water ingestion interval on thermoregulatory responses during exercise in a hot, humid environment (32℃, 80% relative humidity). Eight male university students performed a 60-min cycling exercise (60% of the maximal O_2 uptake) under four separate conditions; no drinking (ND), water ingestion (mineral water) at 5 (D5), 15 (D15), and 30 (D30) min intervals. The total volume of water ingestion (TWI) was identical during D5, D15, and D30, and equal to the amount of fluid lost in sweat during ND. TWI was divided equally by the number of drinking times in each experiment. During exercise, both rectal and mean skin temperature were lower in D5 than those in the other conditions (p<0.05). There was no significant difference in total sweat loss between the four conditions, however, evaporative sweat loss and sweat efficiency (evaporative sweat loss/total sweat loss) were significantly (p<0.05) higher in D5 than those in the other conditions. These results suggest that the shorter water ingestion interval increases evaporative sweating and attenuates higher body temperature during exercise in a hot, humid environment.

body temperature

evaporative sweat loss

water ingestion

prolonged exercise

Medical sciences [ 490 ]

jpn

日本体力医学会

日本体力医学会

本文データは学協会の許諾に基づきCiNiiから複製したものである

[ISSN] 0039-906X

[NCID] AN00137986

[NAID] 110001936316