Purpose: To examine the effects of an 8-week walking program on serum lipids, circulation matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in post-menopausal women. Method: Body weight, percent body fat, body mass index, estimated maximal oxygen consumption, blood lipids, matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1 concentrations were assessed and their matrix metalloproteinase-9/tissue inhibitor of metalloproteinase-1 molar ratios were calculated in exercise (n=12) and control (n=12) groups. Exercise group completed an eight-week walking program at moderate (similar to 6.29 +/- 0.15km/h; similar to 62% maximum heart rate reserve) intensity. Results: Significant changes in estimated maximal oxygen consumption, systolic and diastolic blood pressures, body weight, and body mass index (p<.05) were determined in exercise group. However, there were no significant changes in the measured blood lipids (triglyceride, cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol), matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1 concentrations, and matrix metalloproteinase-9/tissue inhibitor of metalloproteinase-1 molar ratio of exercise group, except for a nearly significant change in tissue inhibitor of metalloproteinase-1 level (p=.092). We determined no significant changes in any of the measured parameters in control group. Conclusion: Despite its protective effects against coronary heart disease risks, the duration and intensity of this program is not sufficient to cause significant changes in blood lipids, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1 concentrations. A higher-intensity, longer-duration program accompanied with diet is proposed
