The Influence of Exercise on the Growing Rat in the Presence and Absence of Vitamin A

Abstract

Experiments carried out with carefully selected groups of rats as experimental subjects yielded data to show that under comparable conditions of experimentation less food was consumed, smaller increases in body weight were made and less severe symptoms of vitamin A deficiency developed when the animals were forced to exercise than when allowed to exercise voluntarily or when confined in the usual type of cage. Although animals maintained under the condition of forced exercise exhibited the greatest efficiency of food utilization, they voided the greatest number of fecal pellets, thus indicating the beneficial effect of exercise on intestinal motility. Animals maintained under the condition of voluntary exercise and which received daily allotments of vitamin A were more active physically than litter mates which did not receive the vitamin A supplement, further indicating a relationship between completeness of diet and physical activity.