Effects of exercise on the utilization of soleus muscle as the countermeasures for prevention of atrophy caused by inhibition of antigravity activity were studied in 7 healthy male subjects. Electromyogram (EMG) activities in soleus were recorded during 1) treadmill walking at 4 and/or 6 km/hr, with 0, 6, 10, and/or 15% uphill inclination, 2) cycling at 70, 130, and/or 170W, by pedaling using arch or front sole, and 3) weight lifting (isometric and/or squat push up) by whole sole or front sole. The greater EMG levels were observed, when the load was increased and the subjects pedalled by front sole. EMGs were also greater, when the weight lifting was performed by using front sole than whole sole. These results clearly suggested that plantarflexion of ankle joints are essential for stimulation of soleus. As for the walking, two different patterns were noted. EMGs in subjects, who step on the floor using heel, were increased when the inclination and speed were elevated. But those in other subjects, who step on the floor using whole sole, were decreased when the work intensities were increased. It is suggested that the individual differences in the walking patterns should be considered for the prescription of walking exercise. Roles of afferent input on the regulation of protein expression in brain were also investigated in adult rats. Deafferentation was performed bilaterally at L4-6 segmental level of spinal cord. Expression of proteins related to glycolitic enzymes and inhibition of cell death was lowered in hypothalamus and thalamus by deafferentation. But the responses in hippocampal proteins were minor. It is suggested that afferent input, which is influenced by activity of leg muscles, plays an important role in the regulation of brain function.

DESCENTE SPORTS SCIENCE Vol.32/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE