Effects of the treadmill walking exercise on the biochemical bone markers.

Objective: To study the effects of moderate-intensity treadmill walking exercise on the biochemical bone markers in the menstruating and menopausal women.

Study Design: Experimental study.

Setting: Department of Rehabilitation Medicine, King Chulalongkorn Memorial Hospital.

Material And Method: Twenty-two healthy volunteer women at the age of 30-70 were recruited: 11 menstruating women and 11 menopausal women. The exercise consisted of the treadmill walking exercise, intensity of 50% of heart rate reserve, for the duration of 30 minutes, at the frequency of 3 times a week, over a 3-month period. Serum beta CTx, PINP and NMID osteocalcin were measured at the baseline and in the 1st, 2nd, and 3rd months.

Results: Twenty women: 11 menstruating women and 9 menopauses completed the exercise protocol. The baseline characteristics including age, body mass index, serum beta CTx, PINP and NMID were statistically different. The serum beta CTx and NMID levels were decreased from the baseline from Month 1 to 3 in both menstruating and menopausal groups. Serum PINP was not significantly changed in the 1st and 2nd months except the significant decreasing in the 3rd month in the menstruating women. There were no significant differences of bone marker changes between the menstruating women and the menopauses. The biochemical bone markers' levels (beta CTx, PINP and NMID) had the strong correlations analyzed by Pearson's correlation coefficients (> 0.8 with p-value < 0.001).

Conclusion: The present study clearly demonstrates that the moderate intensity treadmill walking exercise for 30 minutes, 3 times a week reduces bone resorption and bone turnover markers in both the menstruating women and the menopauses after the first month until the third month of the experiment. Although the bone formation markers had a tendency of decreasing after exercising, the significant changes showed only in the 3rd month in the menstruating group. All of the bone markers including beta CTx, NMID osteocalcin and PINP were highly correlated.