Acute effects of a single exercise session on serum lipids in untrained men.

Acute reductions in triglycerides and calculated low density lipoprotein cholesterol with little change in high density lipoprotein cholesterol have been reported in trained men after a single exercise session. To examine if a similar acute exercise effect occurs in sedentary subjects, wer measured triglycerides, total cholesterol, and high density lipoprotein cholesterol in eight sedentary men before and for 66 hours after a single 30-minute exercise session. The exercise was designed to simulate a typical exercise training session for untrained subjects. An isolated reduction in estimated low density lipoprotein cholesterol was observed 66 hours after the exercise. All other serum lipid measurements at 5 minutes and 1, 4, 18, 42, and 66 hours after exercise did not differ from pre-race concentrations. Consequently, the reductions in triglycerides and low density lipoprotein cholesterol and increase in high density lipoprotein cholesterol reported in previously sedentary subjects after exercise training are a chronic rather than an acute exercise effect.