Effects of an mHealth physical activity intervention to prevent osteoporosis in premenopausal women. A randomized controlled trial.

OBJECTIVES: It is critical to develop prevention strategies for osteoporosis that reduce the burden fractures place on individuals and health systems. This study evaluated the effects of an mHealth intervention that delivered and monitored a non-supervised exercise program on bone mineral density (BMD). DESIGN: Randomized controlled trial. METHODS: 60 premenopausal women aged 35-50 years were divided into an intervention group (IG) and a control group (CG). The IG followed a 6-month intervention aimed at increasing osteogenic physical activity, guided by two daily goals: walking at least 10,000 steps and completing 60 impacts over 4 g of acceleration. These goals were monitored using a wearable accelerometer linked to an mHealth app. The CG maintained their regular lifestyle and wore the accelerometer without feedback. BMD was estimated using dual-energy X-ray absorptiometry (DXA) scans at baseline and after 6 months, with group-by-time analyses conducted using ANCOVA. The intervention's impact on physical fitness and activity habits was also evaluated. RESULTS: 46 participants completed the study (IG = 24; CG = 22). The IG showed significant improvements compared to the CG in femoral neck BMD (IG: +0.003 ±â€¯0.029 g/cm2 vs CG: -0.027 ±â€¯0.031 g/cm2), trochanter BMD (IG: +0.004 ±â€¯0.023 g/cm2 vs CG: -0.026 ±â€¯0.030 g/cm2), and total hip BMD (IG: +0.006 ±â€¯0.043 g/cm2 vs CG: -0.040 ±â€¯0.048 g/cm2). The IG also demonstrated significant improvements in physical fitness measures, including peak torque and power at various speeds and positions. No adverse events related to the intervention were reported. CONCLUSIONS: This non-supervised physical activity intervention delivered by wearable-technology and an mHealth app was effective in improving BMD, suggesting its potential for osteoporosis prevention.