Compositional influence of movement behaviors on bone health during aging

Introduction and Purpose: Physical activity (PA) is considered the best nonpharmacological treatment for the decrease in bone mass (BM) produced during aging. Therefore, it is essential to assess how the time spent in PA is distributed to control further changes. This work examines the relationship between movement behaviors and BM during aging, using compositional data analysis. Methods: We studied 227 older people 65 to 94 yr old (102 men and 125 women), divided by sex and bone status, over a period of 4 yr. Time spent in sedentary behavior (SB), light PA (LPA), and moderate to vigorous PA (MVPA), was assessed using accelerometry. BM was determined by dual-energy x-ray absorptiometry. Results: The changes in MVPA were positively associated with the rate of BM decay at spine and leg in the whole sample and men's subgroup (P <= 0.05). In women, the rate of BM decay at spine and Ward's triangle were negatively associated with SB changes, and BM decay at femoral neck and Ward's triangle were positively associated with LPA (P <= 0.05). Conclusion: Increasing MVPA related to other movement behaviors produces improvements in the rate of bone change in older men, whereas to increase LPA and maintain MVPA would be the best approach to enhance BM in older women