EFFECTS OF 4 DIFFERENT SINGLE EXERCISE SESSIONS ON LIPIDS, LIPOPROTEINS, AND LIPOPROTEIN-LIPASE

The purpose of this study was to determine the threshold of exercise e nergy expenditure necessary to change blood lipid and lipoprotein conc entrations and lipoprotein lipase activity (LPLA) in healthy, trained men. On different days, 11 men (age, 26.7 +/- 6.1 yr; body fat, 11.0 /- 1.5%) completed four separate, randomly assigned, submaximal treadm ill sessions at 70% maximal O-2 consumption. During each session 800, 1,100, 1,300, or 1,500 kcal were expended. Compared with immediately b efore exercise, high-density lipoprotein cholesterol (HDL-C) concentra tion was significantly elevated 24 h after exercise (P < 0.05) in the 1,100-, 1,300-, and 1,500-kcal sessions. HDL-C concentration was also elevated (P < 0.05) immediately after and 48 h after exercise in the 1 ,500-kcal session. Compared with values 24 h before exercise, LPLA. wa s significantly greater (P < 0.05) 24 h after exercise in the 1,100-, 1,300-, and 1,500-kcal sessions and remained elevated 48 h after exerc ise in the 1,500-kcal session. These data indicate that, in healthy, t rained men, 1,100 kcal of energy expenditure are necessary to elicit i ncreased HDL-C concentrations. These HDL-C changes coincided with incr eased LPLA.