The purpose of this study was to clarify the characteristics of ventilatory and circulatory responses at the onset of voluntary exercise and passive movement in sprinters. Eleven male university sprinters and 11 male untrained subjects participated in the present study. Voluntary exercise consisted of leg extension-flexion movement for 20 s with weights corresponding to 5% of each subject's body mass attached to each ankle. Passive movement was achieved without weights by the experimenter alternately pulling ropes that were connected to the subject's ankles for the same period and frequency as during voluntary exercise. In the present study, the following results were found: (1) the magnitude of relative changes (gain) of minute ventilation at the onset of passive movement in the sprinters was significantly smaller than that in the untrained subjects [mean (SEM) 33.3 (2.9) vs 61.7 (6.4)%, P<0.05]; (2) the time for reaching one-half of the gain (response time) of heart rate at the onset of voluntary exercise and passive movement in the sprinters was significantly slower than that in the untrained subjects [2.5 (0.2) vs 1.7 (0.2) s in voluntary exercise and 3.4 (0.8) vs 1.5 (0.1) s in passive movement, P<0.05]; (3) the gain and response time of mean blood pressure at the onset of voluntary exercise and passive movement showed no significant differences between the two groups. It is concluded that sprinters show slowed heart rate response at the onset of voluntary exercise, and attenuated ventilatory and slowed heart rate responses at the onset of passive movement as compared with untrained subjects.

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Lactate, glycerol, and catecholamine in the venous blood after 400-m and 3,000-m runs were determined in eight sprint runners, eight long distance runners, and seven untrained students. In 400-m sprinting, average values of velocity, peak blood lactate, and adrenaline were significantly higher in the sprint group than in the long distance and untrained groups. The mean velocity of 400-m sprinting was significantly correlated with peak blood lactate in the untrained (r = 0.76, P less than 0.05) and long distance (r = 0.71, P less than 0.05) groups, but not in the sprint group. In the 3,000-m run, on the other hand, average values of velocity and glycerol were significantly higher in the long distance group than in the sprint and untrained groups, but there are no significant differences in lactate levels between the three groups. These results suggest that 1) performance in 400-m sprinting may depend mainly upon an energy supply from glycolysis in the long distance and untrained group, but in the sprinters is influenced not only by glycolysis, but also by other factors such as content of ATP or force per unit muscle cross-sectional area; 2) peak blood lactate obtained after 400-m sprinting may be used as a useful indication of anaerobic work capacity in the long distance and untrained groups, but not in the sprinters. 3) high speed in the 3,000-m run could be maintained in the long distance runners by means of a greater energy supply from lipid metabolism as compared with sprinters or untrained subjects.

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