The effects of eight-week walking programs of two different intensities on serum lipids and circulating markers of collagen remodelling in humans

Buyukyazi G.

The effects of eight-week walking programs of two different intensities on serum lipids and circulating markers of collagen remodelling in humans

Date

2008

Authors

Buyukyazi G.

Abstract

Aim: This study examined the effects of eight weeks of walking programs on serum lipids, circulation matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). Methods: Thirty-seven premenopausal women (30-55 years) completed eight weeks of walking programs either at moderate (∼5.25 ± 0.28 km/h; ∼53% maximum heart rate reserve (HRRmax) or high-intensity (∼7.33 ± 0.24 km/h; ∼73% HRRmax). Non-walking, sedentary women served as controls. Estimated VO2max was assessed with a 2 km walking test; body composition was measured using body composition analyzer; lipid, MMP-9, and TIMP-1 concentrations were measured in serum. Results: After eight weeks, estimated VO2max improved in high-intensity walking group (HIWG; p < 0.01) and in moderate-intensity walking group (MIWG; p < 0.05); BMI, and percent body fat decreased (p < 0.05) in both exercise groups. Only HIW caused significant reductions in total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and MMP-9 levels (p < 0.05); we found no significant changes in high-density lipoprotein-cholesterol and triglyceride levels in any of the groups. Exercise did not cause any significant changes in TIMP-1 levels apart from a nearly significant reduction in HIWG (p = 0.084). Conclusion: Walking programs with different intensity bring about favorable changes; but significant improvements for protective effects against cardiovascular diseases may be attained only with high-intensity walking programs due to the reduction in TC, LDL-C and MMP-9 levels. © 2008 Elsevier Masson SAS. All rights reserved.