Objective: This study aimed to clarify changes in planter pressure at the 1, 2, 5 metatarsal head, and muscle activities resulting from exercise of the peroneus longus (PL) or tibialis posterior (TP) muscles. Method: Nine subjects (3 male, 6 female) were recruited. Before and after exercise, planter pressure at the metatarsal heads and the activities of PL, TP, tibialis anterior, and soleus muscles were recorded during heel raising using electromyography and a foot sensor. The first exercise was a maximal isometric contraction of the PL and peroneus brevis (PB). The second was contraction of the TP, and the third was of all three, the PL, PB, and TP. Result: The amount of planter pressure at the first metatarsal head increased after PL exercise. The standard deviation at the second metatarsal head decreased after PL and TP exercise, but showed no change after PL exercise. Conclusion: After PL and TP exercise, heel raises were possible with few perturbations at the metatarsal head. After PL exercise, the amount of planter pressure at the first metatarsal head increased, but there was no change in perturbations. The results show that it is necessary to consider the effect of short time exercise.

We studied the effects of exercise on the blood fluidity. The subjects were 18 healthy males (21.6±0.8 yr, control : 5, soccer : 9, gymnastics : 4) . We measured the filtration time of whole blood by the Nuclepore filtration method as an index of blood fluidity. The filtration time at rest in the control group, soccer group, and gymnastics group was 59.8±11.9s, 42.5±15.1 s, 28.6±6.7s, respec tively. The filtration time at rest in the soccer group was significantly shorter than that in the control group (p<0.001) . There were no significant differences in filtration time at rest between the control and gymnastics groups, and between the soccer and gymnastics groups. The filtration time after single aerobic exercise was significantly prolonged compared with that before (p<0.001) . The filtration time before and after anaerobic exercise and muscular exercise was not significantly changed. The degree of filtration time prolongation was significantly lower in groups who drank water compared to groups who did not (p<0.001) . The effect of taking a sauna on filtration time was not significant. These results indicates the effect of aerobic exercise on blood fluidity, and the importance of water intake during exercise.