Effects of exercise cessation on lipids and lipoproteins in distance runners and power athletes.

The purpose of this study was to determine the effects of short-term exercise cessation on lipid and lipoprotein profile and insulin sensitivity in highly trained runners (n = 12; mean age 19.9 years) and power athletes (n = 12; mean age 24.4 years). Following 14 days of exercise cessation, running time to exhaustion and maximal oxygen uptake decreased by 9.2% and 4.8% (P < 0.05) in the runners, while in the power athletes one repetition maximum squat and bench press did not change (P > 0.05). No changes occurred in body composition. Data from a 2-h oral glucose tolerance test revealed an impairment of the glycemic state in all athletes (P < 0.05). In contrast, exercise cessation did not significantly (P > 0.05) alter plasma levels of cholesterol, triglycerides, and low density (LDL) and high density lipoprotein (HDL). No changes were observed in HDL2, HDL2b, and HDL3 subfractions, LDL diameter, and qualitative LDL pattern (P > 0.05). These data thus suggest that despite a decrease in insulin sensitivity, short-term exercise cessation, independent of exercise mode, was insufficient to alter plasma lipid and lipoprotein profiles in well-trained athletes.