A comparison between the effects of the walking exercise with and without weighted vests on bone resorption and health-related physical fitness in the working women.

The purpose of the present study was to compare the effects of walking exercise with and without weighted vests on bone resorption and health-related physical fitness in the working women. Forty-eight female staff of Chulalongkorn University who were 30-60 years old voluntarily participated in the study. The subjects were randomly assigned into two groups: the experimental group performing the walking exercise wearing the weighted vests (EW, n = 24) and the control group performing the walking exercise without wearing the weighted vests (E, n = 24). The treatment was the 30-minute walking exercise on treadmill at 0% of grade, 3 times per week for 12 weeks at the intensity of 65-75% of the maximal heart rate. The first two weeks, the EW group walked without the weighted vests. Starting from the third week, the vest load was progressively increased each week with 2% of each participant's body weight until it reached 8% in the sixth week. Bone formation (PINP), bone resorption (beta-crossLaps) and health-related physical fitness were collected. The obtained data were analyzed in terms of the mean, standard deviation, paired t-test, one way analysis of covariance, one way analysis of variance with repeated measure and the multiple comparisons by using Least Significant Difference (LSD) at the 0.05 level. Prior to the experiment, the mean age and the MD of the experimental group were 41.54 +/- 8.08 yrs and -0.57 +/- 1.14, respectively. The control group has the mean age of 46.00 +/- 7.47 and BMD of -0.53 +/- 1.09. After 12 weeks of the training, there was no statistical difference in bone formation marker, bone resorption marker and health-related physical fitness between the experimental group and the control group. Moreover, the reduction of 19.143% and 21.849% of bone resorption marker in Group EW and Group E, respectively were found. Other health-related physical fitness, e.g., the muscle strength and endurance of legs and arms and the maximum oxygen uptake in both groups were significantly improved. In conclusion, the walking exercise with and without the weighted vests can reduce bone resorption and improve health-related physical fitness. This type of exercise is an alternative way to prevent bone resorption for the working women.