Effect of exercise intensity and frequency on lipid levels in men with coronary heart disease: Training level comparison trial

The objective of the Training Level Comparison Trial was to determine whether a more intense exercise program versus a less intensive program has additional favorable effects on blood lipids in men with coronary heart disease (CHD) over a 12-month period. The study—a randomized, controlled trial conducted at 2 clinical centers—enrolled 185 patients with documented CHD. A simple randomization procedure led to unequal numbers of patients in the 2 interventions: 82 in the low-intensity and 103 in the high-intensity group. Target heart rate during exercise corresponded to 50% of maximum oxygen uptake (VO2 max) ± 5 beats/min in the low-intensity group and 85% ± 5 beats/min in the high-intensity group. The intensity of exercise made little difference on lipid improvements. However, the attendance rates for the 6- and 12-month periods (percentage of total exercise sessions attended) were significantly related to increased high-density lipoprotein (HDL) cholesterol (rs [Spearman rank correlation coefficient 0.20 to 0.26, p <0.05]), and decreases in the ratios of low-density lipoprotein (LDL)-to-HDL cholesterol (LDL:HDL, rs = −0.24 to −0.28, p <0.01) and total-to-HDL cholesterol (total:HDL, rs = −0.25 to −0.29, p <0.01) at 6 and 12 months. The relation of the attendance rate to LDL:HDL and total:HDL ratios remained significant in repeated-measures regression analysis. Exercise frequency may be more important than intensity in improving HDL cholesterol and LDL:HDL and total:HDL ratios in men with CHD.