Background--Physical exercise is associated with a decreased risk of cardiovascular disease, which may be partly caused by the effect of exercise on the lipoprotein profile. The most consistent effect of exercise on lipoprotein metabolism is an increase in high-density lipoprotein (HDL).

Methods and Results--Parameters of reverse cholesterol transport (RCT) in 25 endurance-trained male athletes were compared with 33 age-matched males enjoying an active lifestyle. VO₂max was higher in athletes than in controls (53.4±1.2 versus 38.8±1.0 mL/min per kg; P<0.01). The following differences in parameters of RCT were found: (1) plasma HDL cholesterol and apoA-I levels were higher in athletes compared with controls (1.7±0.1 versus 1.4±0.1 mmol/L; P<0.001; and 145±2 versus 128±3 mg/dL; P<0.001, respectively). Both correlated with VO₂max up to the value of 51 mL/min per kg; (2) pre₁-HDL was higher in athletes than in controls (54±4 versus 37±3 µg/mL; P<0.001) and correlated positively with VO₂max; (3) lecithin cholesterol: acyltransferase activity was higher in athletes (29.8±1.2 versus 24.2±1.4 nmol/µL per hour; P<0.005); and (4) the capacity of plasma to promote cholesterol efflux from macrophages was higher in athletes (18.8%±0.8% versus 16.2%±0.3%; P<0.03).

Conclusions--The likely reason for higher HDL concentration in physically fit people is increased formation of HDL from apoA-I and cellular lipids.