the effect of participation in a physical fitness programme of moderate intensity on plasma lipoprotein cholesterols, total cholesterol, triglycerides and apolipoprotein-a levels was investigated. forty-nine inactive individuals participated in a sixteen week exercise programme that consisted of three sessions weekly with one and one-half hours in each session. the results were compared with those of a non-participating group. results suggest that a programme of physical exercise of moderate intensity of a relatively short duration (sixteen weeks) can have a beneficial effect by modifying the plasma lipid constituents in potentially high risk individuals, particularly those over 40 years who have low hdl-cholesterol blood levels.