Andrés Mármol-PérezEsther Ubago‐GuisadoJosé J. Gil‐CosanoAndrea Rodríguez-SolanaFrancisco B. OrtegaM. GonzálezJuan F. Pascual-GázquezFrancisco Jesús Llorente‐CantareroCristina Cadenas‐SánchezVicente Martínez‐Vizcaíno2026-03-222026-03-22202510.1101/2025.04.21.25325629https://doi.org/10.1101/2025.04.21.25325629https://andeanlibrary.org/handle/123456789/83898Citaciones: 1Abstract Pediatric cancer survivors remain at increased risk of low areal bone mineral density (aBMD) after treatment. We investigated the effects of a 9-month online bone-strengthening exercise intervention on the femoral neck aBMD Z-score (primary outcome), and other bone health parameters measured using dual-energy X-ray absorptiometry at the hip, total body, and lumbar spine in young pediatric cancer survivors. A total of 116 participants were randomized into the exercise or control groups (N = 58 in each). 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). 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 a small effect size 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). No adverse events were reported. Adherence was high (87.4%). 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. This intervention is safe, well-tolerated, and may contribute to reduce the risk of bone impairments during adulthood. Trial Registration isrctn61195625 dated April 2, 2020. One Sentence Summary A 9-month online bone-strengthening exercise intervention does not improve bone health at the femoral neck in pediatric cancer survivors.enRandomized controlled trialMedicineBone healthPhysical therapyIntervention (counseling)Cancerpreprint