Effects of a bone-strengthening exercise intervention on bone health in pediatric cancer survivors: A Randomized Controlled Trial

Abstract Objectives To investigate the effects of a 9-month online bone-strengthening exercise intervention on the femoral neck areal bone mineral density (aBMD) Z-score and other bone health parameters. Design Assessor-blinded randomized controlled trial with 2 parallel arms. Setting Sport and Health University Research Institute (iMUDS). Participants A total of 116 pediatric cancer survivors aged 6–18 years (12.1 ± 3.3 years; 42% girls). Interventions Before intervention, all participants received dietary counseling on calcium and vitamin D intake. The exercise group performed a 9-month periodized video-recorded bone-strengthening exercise intervention based on squats and jumps (3–4 days/week for 10–20 min/session) at home. Main Outcome Measures Primary (femoral neck aBMD [g/cm²]) and secondary outcomes (aBMD and bone mineral content [BMC, g]) were measured using dual-energy X-ray absorptiometry at the hip regions (femoral neck and total hip), total body, and lumbar spine (mean of L1–L4) at baseline and 9-month post-intervention. Results No between-group differences in femoral neck aBMD Z-score (Cohen's d = -0.08, P = .706) and aBMD Z-score outcomes were observed post-intervention. However, the intervention showed small effect sizes on the total hip, with a borderline non-significant improvement in aBMD Z-score (Cohen's d = 0.35, P = .054) and a significant improvement in BMC Z-score (Cohen's d = 0.38, P = .039). Conclusions The 9-month online bone-strengthening exercise intervention did not increase the femoral neck aBMD Z-score; however, it improved the overall BMC Z-score at the hip in young pediatric cancer survivors.