Six male students volunteered to take part in the present study. They walked wearing regular athletic shoes and heel-less shoes at the constant speed of 60 m/min, 80 m/min, 100 m/min and 120 m/min for 10 min on a treadmill at 0% grade. Heel-less shoes means that the heel and toe of the shoes were cut at 15° and 10°, respectively. Step frequencies, stride were measured during each walking. Calf blood flow (CBF) and blood lactate, plasma adrenaline and noradrenaline concentrations were measured at rest and immediately after walking exercise. Heart rate was monitored during the experiments. There was no significant difference in step frequencies and stride between regular athletic shoes and heel-less shoes during each walking speed. During walking at speeds ranging from 60 m/min to 100 m/min in regular shoes, 60 m/min to 80 m/min in heel-less shoes, the CBF increased linearly in relation to walking speed. The CBF showed its highest mean value at 80 m/min in heel-less shoes, at 100 m/min in regular athletic shoes walking. However, at higher walking speeds than these, it decreased in both shoes. The CBF immediately after 80 m/min of speed was higher in walking with heelless shoes compared to regular athletic shoes. Blood lactate concentration after walking with heel-less shoes at the speed of 120 m/min was significantly higher than basal level, but it remained unchanged after walking with regular athletic shoes in comparison to the level before the walking exercise. Heart rate and plasma noradrenaline concentrations at the speed of 120 m/min in heel-less shoes walking was significantly higher than in regular athletic shoes.
　In conclusion, the CBF wearing heel-less shoes at the speed of 80 m/min was higher than regular athletic shoes. At even higher speed (120 m/min) the increase in glycogen breakdown in heel-less shoes walking might be due to the increase of sympathetic nerve activity, causing lower CBF.

DESCENTE SPORTS SCIENCE Vol.20/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE