The aim of this study was to investigate quantitatively the power ability of middle and older aged men in the vertical jump.
And, we would try to point out the changes with increasing ages and the influences of the environments factor to the power ability.
Based on the environment point of view, we put an emphasis and consideration on those who did physical exercises and also those who drove a car in a daily life.
Subjects were the health 201 men who visited the sports sauna training center of national stadium for physical exercises.
The power was calcurated from the force and velocity concerning of jumper's C.G. during the take off motion. The force was measured by using a strain gage type tranceducer, and the velocity was calcurated by integrating the equation of motion about of C.G.
Result:
The power ability of middle and older aged men in the vertical jump decreased with increasing ages.
The rate of decrease with every 5 years of age was 0.248 horse power, 2.960×10^-3 horse power in the maximum power and maximum power per body weight.
In comparison with the power ability of 25 years old, the power ability, in terms of maximum power per body weight, of 35 years old, 45 years old, 55 years old were 90.8%, 81.1%, 59.0%, respectively.
There were evidently differences between trained men and untrained men, and then car driver and no car driver in the power ability. The differences of maximum power per body weight were 12.190 × 10^-3 horse power, 9.231×10^-3 horse power, respectively.

Recently, the popular usage of the sauna bath has been greatly increased but this is not necessaeily based upon scientific ground.
This investigation has been made on the most ideal usage time with special emphasis on duration of time in the actual sauna room.
The usage pattern, in view of the times of taking the sauna room and the cold water, has been established.
And then the influences on the body function were measured.
The usage pattern were as follows (Repetition were all 3 times)
(1) 5 minutes stay in the sauna and 1 minute in the water
(2) 7 minutes stay in the sauna and 1 minute in the water
(3) 7 minutes stay in the sauna and 2 minutes in the water
(4) 10 minutes stay in the sauna and 2, 5 minutes in the watar
The result were as follows
1. The usage pattern (1) gave the good result for the function of whole body reaction time, patellar-tendon reflex time, maximum power of vertical jump.
Another usage pattern (2), (3), (4) gave the wrong result for those function.
2. There were no remarkable differences blood pressure, heart rate and skin temperature among the usage pattern (1), (2), (3), (4) .
3. Oxygen intake in the usage pattern (2) gave a large value than the usage pattern (1) .
In the view of the energy expenditure, it was recognized that the usage pattern (2) was the best usage.