Indirect Determination of Maximal Oxygen Intake at Different Air Temperature Conditions.

Abstract

The purpose of this study is to make a nomogram for estimating maximal oxygen intake at 20°C, 30°C and 40°C of air temperature and to investigate the reliability and validity of it.Two male subject groups volunteered for this study. Group I consists of students of Kyushu Institute for Design Research, none of them has a career as an athlete or special experiences of physical training. Group II is students of Department of Physical Education in Hiroshima University. Between both the groups, there is a large difference in physical resources (Table 1), and the significance was confirmed by the analysis of variance in the cases of maximal oxygen intake and body weight.The heart rate during submaximal step works increases as air temperature rises from 20°C to 40°C, though the oxygen intake shows no obvious changes (Table 3). Therefore, the coefficient of regression of %Vo.max on heart rate decreases gradually as the temperature rises (Table 5). According to the regressions, a nomogram was constituted for estimating maximal oxygen intake from the heart rate and oxygen intake during submaximal work at different air temperature conditions (Fig. 1).The reliability of this nomogram was investigated by the method of comparing estimated value of oxygen intake by this nomogram with the directly determined maximal oxygen intake and the calculated maximal oxygen intake from the nomogram by ASTRAND & RYHMING. All of the present comparisons showed a higher reliabilty of this nomogram than that by ASTRAND & RYHMING (Tables 3, 4, 6, & 7).The characteristics of the new nomogram were discussed from viewpoints of heat stress, postural effect, race difference, and the others.