Signs of Health and Health Habits among College Freshmen

Abstract

Rats (N=180) were used as subjects in this investigation of the effects of prepubertal physical training on tibial growth, organ and body weights, serum cholesterol levels, basal metabolism, and voluntary exercise habits at puberty and 160 days postpuberty. The animals were assigned to one of three initial treatment groups: sedentary, voluntary exercise, or voluntary plus forced exercise. The sedentary animals were allowed no exercise, the voluntary-plus forced rats were allowed to run at will but also were forced to swim with weights on their tails for 30 minutes daily for 35 days just prior to puberty. At puberty 20 animals from each group were sacrificed. The remaining rats were allowed to exercise voluntarily for the next 160 days. After 160 days a second sacrifice of 10 animals from each group occurred. The trained rats at puberty had lower body weights, greater relative adrenal and testis weights, lower kidney weights, shorter tibias, lower serum cholesterol values, and lower levels of voluntary exercise than the control animals. At 160 days postpuberty the trained rats had lower body weights and lower basal metabolic rates than the control rats.