Combined aerobic and resistance exercise is effective for achieving weight loss and reducing cardiovascular risk factors without deteriorating bone health in obese young adults

PURPOSE: Weight loss reduces cardiovascular risk factors in the obese. However, weight reduction through diet negatively affects long-term bone health. The aim of study was to determine the ability of combined aerobic and resistance exercise (CE) to reduce weight and cardiovascular risk without diminishing bone health. METHODS: Twenty-five young adults participated in an 8-week weight loss CE program. Subjects were allocated to an obese group or a control group by body mass index (BMI). Body weight, BMI, body composition, and bone mineral density (BMD) of the lumbar spine and total hip were measured before and after the CE trial. Serum levels of metabolic markers, including adipokines and bone markers, were also evaluated. RESULTS: Weight loss was evident in the obese group after the 8 weeks CE trial. Fat mass was significantly reduced in both groups. Fasting insulin, homeostatic model assessment-insulin resistance (HOMA-IR), leptin and aminotransferases level were significantly reduced from baseline only in the obese group. High density lipoprotein cholesterol increased in both groups. Hip BMD increased in the obese group. In all study subjects, BMI changes were correlated with HOMA-IR, leptin, and HDL changes. BMI decreases were correlated with lumbar spine BMD increases, lumbar spine BMD increases were positively correlated with osteocalcin changes, and lumbar spine bone mineral content increases were correlated negatively with C-terminal telopeptide of type 1 collagen changes. CONCLUSION: These findings suggest that CE provides effective weight loss and improves cardiovascular risk factors without diminishing BMD. Furthermore, they indicate that lumbar spine BMD might be maintained by increasing bone formation and decreasing bone resorption.