Effect of Eight Weeks of Walking on High Density Lipoprotein Cholesterol

Background and Objectives: Increasing HDL-C has been proven to reduce the risk of CHD. Several trials have demonstrated that exercise training can increase HDL-C. The objective of this study was to investigate a dose response relationship between exercise intensity and HDL-C in sedentary Indians who are otherwise healthy.

Method: 94 Participants were randomized to one of the four groups. Group A served as the control group with no exercise and group B (Low intensity), C (Moderate intensity) and D (High intensity) were administered exercise at 50 - 60%, 60 - 70% and 70 - 80% of Heart Rate Reserve (HRR) respectively. Supervised exercise training was administered for five days per week for eight weeks. HDL-C was measured using direct homogenous method and all other plasma lipid measurement was performed before and after eight weeks of intervention.

Results: We found that there was no significant change in HDL-C between (p = 0.17) and within groups. HDL-C increased by 1.75 mg/dl in the high intensity exercise group, decreased by 1.78 mg/ dl in the moderate intensity group, reduced by 0.13 mg/dl in the low intensity group, and. increased by 0.83 mg/dl in the control group.

Interpretation and Conclusion: Improvement of 1 mg/dl has been associated with significant CHD risk reduction. There is lack of evidence for a dose response relationship between exercise intensity and HDL-C. Even though there was no statistically significant increase in HDL-C the present investigation suggests that aerobic exercise administered at 70 - 80% HRR appears to improve HDLC in short term as there was a clinically significant improvement of 1.75 mg/dl.