High density lipoprotein cholesterol, habitual physical activity and physical fitness.

The relationships between habitual physical activity and fitness parameters and fasting serum high density lipoprotein cholesterol (HDL-C), total cholesterol (TC), and triglycerides (TG) were assessed in 357 men aged 30-59 years (mean 44, SD 5). A progressive submaximal power output test (PWC150), a 1-min sit-up test, and a 3-day activity energy expenditure record were obtained for each subject. HDL-C, TG, and HDL-C/TC were significantly associated with the fitness indices (PWC150 and sit-ups), but not with the mean daily energy expenditure computed from a 3-day activity record. However, when the subjects were stratified according to the maximal level of intensity reported in the work and leisure energy expenditure record, a relationship between maximal exercise or work intensity and the concentration of HDL-C and TG, and the ratio HDL-C/TC was found. When adjusted by multiple regression procedures for age, alcohol consumption, cigarette smoking, socio-economic status, fatness level, and TC, or TG, or HDL-C, as appropriate, these relationships became nonsignificant, with the exception of TG and PWC150. These results suggest that habitual physical activity of light intensities is not a major determinant of HDL-C, TC, and HDL-C/TC; it could, however, have a small but significant role in TG. In addition, data suggest that periods of exercise of higher intensity, i.e. with an energy cost of about 6 mets and more, could be a sensible mean to influence serum blood lipid levels.