Effect of regular exercise on cold-induced vasodilation / 体力科学

ABSTRACT

Eighteen male college students who exercised regularly (the trained group) and 20 students who did not participate in regular exercise activities (the control group) were evaluated.<BR>Cold-induced vasodilation (CIVD) and maximal oxygen intake (VO<SUB>2</SUB>max) for each student were measured in May for four consecutive years. In addition, the motor capacity test devised by the Ministry of Education was given to each student. CIVD and values of motor capacity obtained from the students are summarized as follows;<BR>A. The motor capacity test consists of five items (motor skills) . There was no significant difference in muscle strength between the trained group and the control group. The degrees of improvement in explosive power and endurance capacity over the three years were greater in the trained group. It was significant that the degree of improvement in the total scores for the motor capacity test over the three years was 21% in the trained group in contrast to only 8% in the control group. While VO<SUB>2</SUB>max increased markedly in the trained group, it remained almost unchanged in the control group. The degress of improvement in VO<SUB>2</SUB>max over the three years were 25% in the trained group and 8% in the control group. The values in the control group were almost the same as the physical fitness standards, but those of the trained group were higher than the standards.<BR>B. Mean skin temperature and temperature at first rise in the trained group were higher throughout the three years than those in the control group. The time of temperature rise became shortened over three years in the trained group, but in contrast became rather longer in the control group. The range of variations in the amplitude of temperature was 9°C-13°C in the trained group and around 10°C in the control group. Resistance index (RI) of the trained group was higher in the first year; by the time the students became seniors, there was a 43% increase in RI. In contrast, RI in the control group was almost unchanged. The degree of improvement over the three years was 10% in the latter group.<BR>C. The correlation coefficient of RI with scores from the motor capacity test was 0.499 in the trained group and 0.270 in the control group. The correlation coefficient for all the subjects was 0.605. The correlation coefficient of RI with VO<SUB>2</SUB>max was 0.500 in the trained group, 0.160 in the control group and 0.623 in all the subjects. These values indicate that CIVD values and improvement in motor capacity are closely related, and that the interdependence of these two parameters is particularly strong in trained individuals.<BR>These results indicate that the degree of CIVD is determined not only by genetic factors and chronic exposure to cold temperatures but also by physical training.