Stature, body weight, grip strength, back strength and Sargent jump of city dwellers, covering an age range from children to elderly subjects, were measured in order to study the development and aging of physical fitness.
From these cross-sectional data, growth and aging curves were obtained.
Stature appeared to decrease gradually in adulthood but a secular increasing trend was included in the data, so that in fact hardly any change is notable except in late adulthood.
Body weight seemed to increase to some degree in middle adulthood after secular trends had been removed from the data.
The data for back strength showed more rapid decrease in adulthood, infering that the strength of back muscles decreases in adulthood, though there have been insufficient reports on secular trends of muscle strength. Leg power decreased gradually in a similar way after development during adolescence. Grip strength seemed to change little or increase only slightly in middle adulthood, and to decrease later.
Cross-sectional data contain more secular trends than age-related changes in physique during adulthood. The present data may show roughly some growth patterns at certain ages when the rate of growth and development is high and aging patterns at ages when the decrease in fitness is marked. However, details on personal growth and aging patterns should be studied by the longitudinal method.