[Effects of aerobic physical conditioning on the profile of plasma lipoproteins in a group of healthy volunteers].

To evaluate the effects of aerobic physical conditioning on plasma lipoproteins, we studied 26 previously untrained, apparently healthy, non obese volunteers. All participants underwent a treadmill test performed according to the protocol of Bruce with the direct measurement of maximal oxygen consumption (VO2max). A program of aerobic exercise was prescribed for each volunteer at 70% of their corresponding VO2max. At baseline and at the end of weeks 4, 8 and 12 of the exercise program, cholesterol and triglycerides were measured by enzymatic analysis in total plasma and in the lipoprotein fractions separated by preparative ultracentrifugation and precipitation methods. At the end of week 12, the VO2max measurement was repeated. At the end of the protocol, mean VO2max increased from the value of 39.9 observed at baseline to 94.4 ml/kg/min (p less than 0.01). There were no variations in mean body weight, diet or smoking status of the participants during the exercise program. Cholesterol associated with High-density lipoproteins (C-HDL) increased from 42.5 to 46.1 mg/dl (p less than 0.05). This effect was first noticeable at week 8. We didn't observe significant changes in Total Cholesterol nor the Cholesterol fraction associated with Low-density lipoproteins (C-LDL). Total triglycerides decreased at weeks 4 and 8 but returned to near baseline values at week 12. The C-LDL/C-HDL ratio considered as an index of a high coronary risk decreased from 2.32 at baseline to 2.02 (p less than 0.05) at week 12. Thirteen of the twenty six initial volunteers completed the physical conditioning program as planned, the rest were eliminated at different stages of the protocol due to incomplete adherence to their exercise schedules.(ABSTRACT TRUNCATED AT 250 WORDS)