This study was done to identify the effects of weight-bearing exercise(WBE) on bone metabolism.

WBE was performed for 12 weeks by healthy college women. Bone-related parameters were measured four times during this period by evaluating the immunoradiometric assay and enzyme immunoassay. Bone mineral densities(BMDs) were measured by dual energy x-ray absorptiometry before and after the WBE program. Data was analyzed using t-test, paired t-test, x²-test, and repeated measures ANOVA.

Osteocalcin, a bone formation marker, increased more in the experimental group than in the control group based on the interaction between time and group(F=3.29 p=.024). Little difference between the two groups was found for the other parameters: urinary deoxypyridinoline, insulin-like growth factorI, parathormone, serum calcium, and serum phosphorus without showing any time interaction between the groups. The femoral trochanter BMD rose in the experimental group while that of the control group fell, showing a significant difference for BMD(t=3.06 p=.005). However, there was no significant difference between the two groups for changes in BMD of the forearm, lumbar spine, femoral neck, and femoral ward's triangle.

These findings supported the WBE is beneficial for increasing bone formation in college women and long-term application is needed to substantiate the effects of WBE as a intervention in promotion of bone-health.

To investigate body compositons and bone mineral density(BMD) in college women and to find the relationship between them.

From January to March of 2001, BMD at four parts(forearm, lumbar, femur and whole body), body mass index(BMI), body fat mass(BFM), lean body mass(LBM) and body fat percentage(%Fat) were measured with the Dual Energy X-ray Absorptiometry. Other physical characteristics were measured with a scale, a height measurer, and questionnaires.

Grouping by the BMI, 43.2% showed low weight, and 5% over weight. When applying the percent Fat, 43.8 % was diagnosed as obesity group. The fact indicate that a majority of college women have unbalanced body composition with high percent Fat, compared to their body weight. Assessing the BMD with the WHO standards, 91.4~95.7% of the BMD of forearm and whole body was normal. But, 40.3% and 33.1~43.9% showed osteopenia at lumbar and femur, and 1.4 %, 0.7~7.2% showed osteoporosis. The BMD at all parts showed significant correlation each other(r=.29~.89, p=.001~.000). Body weight and BMI showed correlations to with BMDs at all parts of the body(r=.19~.46, p=.025~.000; r=.18~.45, p=.039~.000). But the percent Fat had a correlation with only femur neck BMD(r=.19, p=.024).

This study showed a majority of healthy college women were exposed to the risk for osteoporosis. Additional study is required to develop nursing interventions to remove the risk factors of osteoporosis. In particular, the acquisition of balanced body composition is necessary, increasing body weight and BMI through the increase of LBM, not through the quantitative increase of BFM.