Effects of exercise with varying energy expenditure on high-density lipoprotein-cholesterol.

To investigate the effect of varying energy expenditure on acute high-density lipoprotein-cholesterol (HDL-C) changes, 12 healthy endurance-trained men completed three- counterbalanced running trials at different energy expenditures: trial 1, 1690.3 (24.4) kJ [mean (SD)]; trial 2, 2529.1 (24.0) kJ; trial 3, 3384.3 (36.6) kJ, with exercise intensity at 75% of maximal oxygen consumption. For each trial, blood samples were collected at 24 h pre-exercise (24 h Pre), immediately post-exercise, 1 h post-exercise, 6 h post-exercise (6 h PE), and 24 h post-exercise (24 h PE). Plasma samples were analyzed for HDL-C, HDL2-C and HDL3-C subfractions, and triglycerides (TG). In addition, post-heparin plasma samples were analyzed at 24 h Pre, 6 h PE and 24 h PE for lipoprotein lipase activity (LPLA) and hepatic triglyceride lipase activity. All samples were corrected for plasma volume changes and compared to 24 h Pre (baseline). When trials were combined, an increase (P < 0.05) in HDL-C was observed 24 h PE, via an increase (P < 0.05) in HDL3-C. An increase (P < 0.05) in LPLA and decrease (P < 0.05) in TG at 24 h PE is suggested to be responsible for the increase in HDL3-C. In conclusion, no difference in HDL-C was observed among trials. However, when trials were combined, an increase in HDL-C was observed, suggesting that an energy expenditure of no greater than 3384 kJ is needed to promote favorable changes in HDL-C.