Smaller decreases in protein and greater decreases in fat may be associated with exercise training before body mass reduction

The effect of exercise training before body mass reduction on body composition and energy storage in the body after body mass reduction was studied in rats. Twenty‐one rats (all 4 weeks old) were divided into two groups, a sedentary (S, n = 10) or exercise (E, n = 11) group. The rats in the E group performed climbing exercise training for 3 weeks. The protein, total lipid and glycogen levels in homogenized carcasses were measured both before and after a 3 day fast (n = 5 – 6). The body mass, a sum of the masses of the excised skeletal muscles and adipose tissues did not differ between the groups before and after the 3 day fast. The difference in the mean body mass before and after the 3 day fast was similar in the S and E groups (S −54.1 vs. E −53.7 g). The difference in the mean protein level was greater in the S than the E group (S −20.1 vs. E −15.6 kcal), while the difference in total lipids was lower in the S than the E group (S −82.7 vs. E −116.3 kcal). Glycogen decreased comparably between the groups (S −0.5 vs. E −0.6 kcal). As a result, the decrease in the energy stored in the body after the 3 day fast was lower by 22% in the S group than in the E group (S −103.3 vs. E −132.5 kcal). Exercise training before body mass reduction may therefore be associated with a smaller decrease in lean body tissues and a greater decrease in adipose tissues.