Exercise training effects on serum lipids of prepubescent boys and adult men

SAVAGE, M. P., M. M. PETRATIS, W. H. THOMSON, K. BERG, J. L. SMITH, and S. P. SADY. Exercise training effects on serum lipids of prepubescent boys and adult men. Med. Sci. Sports Exerc., Vol. 18, No. 2, pp. 197-204, 1986. The effects of 10 wk of exercise training at low (40% V˙O_2max) or high (75% V˙O_2max) intensity on serum lipids and lipoproteins were compared in prepubescent boys and adult men. The final sample size consisted of: 8 boys (mean ± SE age = 8.5 ± 1.96 yr) and 8 men (36.6 ± 3.18 yr) in low; 12 boys (8.0 ± 1.40 yr) and 12 men (36.6 ± 4.09 yr) in high; and 10 boys (9.0 ± 2.08 yr) and 10 men (36.7 ± 4.82 yr) in control. Training involved walking/jogging/running 3 d·wk^-1at a distance which progressed from 2.4 km·d^-1in the first week to 4.8 km·d^-1from the fifth week. Fasting blood samples, collected on 2 d during both pre- and post-training, were assayed for triglycerides, total cholesterol (CHOL), and high density lipoprotein cholesterol (HDL-C). Maximum aerobic power (V˙O_2max) was determined from a treadmill test. Additionally, dietary intake was assessed from a 3-d dietary record and body composition from the sum of 6 skinfolds. The only statistically significant (P < 0.05) changes occurred in HDL-C and CHOL for the high groups. HDL-C decreased following training. CHOL was lower for high than the other groups for the first day post-training only. There were no differences in the changes in HDL-C/CHOL ratio among the groups. V˙O_2maxonly increased in the high groups. Dietary intake and body weight did not change. Further statistical adjustment in lipids for changes in sum of 6 skinfolds did not alter the results. It was concluded that boys and men did not differ in the changes in serum lipids and lipoproteins and cardiorespiratory fitness from 10 wk of exercise training.