ABSTRACT
Objective To observe the effects of aerobic exercise on low-and high-density lipoprotein cholesterol,and to investigate the relationship between exercise intensities and high-density lipoprotein cholesterol (HDL-C) changes.Methods Sixty patients with low HDL-C were randomly allocated into a high intensity exercise group,a moderate intensity group or a low intensity group with 20 in each group.According to each patient's maximal heart rate in a restrictive electrocardiogram exercise test,the different aerobic exercise intensities were formulated as follows.The target heart rate of the high-intensity training group was 90％ of each subject's maximum heart rate; in the moderate-intensity group it was 70％ ; in the low-intensity group it was 50％.All 3 groups jogged on a medical treadmill for 20 minutes every other day with their heart rates monitored at all times.They maintained the target heart rate for 20 minutes.The experiment lasted 2 months.Results In the high intensity group HDL-C increased from 0.81 ± 0.22 to 1.04 ± 0.33 mmol/L after training; in the moderate intensity group it increased from 0.82±0.20 to 1.03 ±0.37 mmol/L; in the low intensity group it increased from 0.79 ±0.25 to 0.82 ± 0.27 mmol/L.That increase in the low intensity group was not statistically significant.After high intensity or moderate intensity training the HDL-C increases were statistically significant,but the difference between the groups was not.After training,in 15 cases among the high intensity group,13 cases from moderate intensity group and in 1 case from the low intensity group the HDL-C level achieved a normal value (≥ 1.04 mmol/L).Comparing the high intensity group to the low intensity group or the moderate intensity group to the low intensity group,there were significant differences in the number of patients who achieved normal HDL-C readings,but there was no significant difference between high intensity group and the moderate intensity group.Conclusion Low intensity aerobic exercise has no obvious effect on low HDL-C levels.High or moderate intensity aerobic exercise can effectively raise the HDL-C level,but there is no significant difference in the fraction of patients reaching normal values between high and moderate intensity aerobic exercise.So moderate intensity is recommended for improving low levels of HDL cholesterol.