Detailed Body Composition Analysis on Female Rats Subjected to a Program of Swimming

Abstract

Previous studies have shown that animals subjected to programs of prolonged endurance exercise have a greater lean body mass than sedentary animals of the same age and body weight. The present study was performed to determine which tissues and body components contribute to the greater lean body mass of female rats subjected to a program of swimming as compared to sedentary animals of the same body weight. Compared to the sedentary controls, the carcasses of the swimmers, after 21 weeks on the swimming program, contained approximately 20 g more lean tissue. The tissue groups contributing to the greater lean body mass were: a) the skin and subcutaneous tissue (3.67 g); b) the heart, lungs, liver, kidneys and blood (4.68 g); c) the intestinal tract, pancreas, uterus, ovaries, mesentary, omentum, and retroperitoneal adipose tissue (4.37 g); d) tail (0.67 g); e) the eviscerated carcass, consisting of the head and neck, spine, ribcage, clavicles, pelvis, and remaining attached musculature, after removal of the front and hind-limb units with attached shoulder and pelvic girdle muscles (6.75 g). There was no hypertrophy of the limb and girdle muscles directly involved in the swimming.