Physiological Effects of Drinking and Clothing during High School Baseball Practises on Players in Heat Environment

Abstract

  Physiological effects of drinking and clothing during Tokushima prefectural high school baseball practices on players in heat environment were discussed.

  The results obtained were as follows : -

  1) By practices for about 4.5h in heat environment, body decreased in weight, sweating volume, heart rate and body temp. (oral-, skin-) increased. But changes for blood pressures (systolic, distlic) were not observable. SpO₂ diminished.

  2) Sweating volume of players in free drinking group was larger than that of the ones in no drinking group, but body weight loss of players in free drinking group by practices was not so large. In free drinking group to have larger sweating volume, the effective sweat increased in volume and water intake was colder by about 22℃ than body temp., these made body temp. fall. And heart rate of the players in no drinking group was more in number than that of the players in free drinking group because of physical load and blood concentration due to sweating. Blood pressures (systolic, distlic) were almost same irrespective of drinking or not during practices.

  3) In case of wearing (underwear) or (underwear ＋ shirt), by being absorved sweat came out from body during practices, both these clothes converted into good conductors of heat. Accordingly, the latter clothes became easier to accept the radiant heat. This tendency of latter clothes, by wetting of sweat, was more remarkable than the former clothes.

  This shirt prevented the evaporation of sweat and made the temp. in clothing climate rise. As the result, body temp. rose, sweating volume increased, body weight became light, and heart rate increased in number. Blood pressure and SpO₂ were not remarkable.