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.

The authors have declared no competing interest.

isrctn61195625

https://www.isrctn.com/ISRCTN61195625

This project (ref. PID2020-117302RA-I00) was funded by A/10.13039/501100011033. Authors also thank the financial support by La Caixa Foundation (Ref: LCF/BQ/PR19/11700007), University of Granada Plan Propio de Investigacion 2021-Excellence actions: Unit of Excellence on Exercise, Nutrition, and Health (UCEENS), and CIBEROBN, Centro de Investigacion Biomedica en Red (CB22/3/00058), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovacion and Union Europea - European Regional Development Fund. AMP was also a recipient of a predoctoral fellowship (FPU20/05530) from the Spanish Ministry of Education, Culture, and Sports. EUG received RYC2022-038011-I funding from MCIN/AEI/10.13039/501100011033 and ESF+. CCS received grants from the European Union Horizon 2020 Research and Innovation Programme under the Marie Sklodowska Curie grant agreement No. 101028929. FBO research activity was further supported by the by the Spanish Network in Exercise and Health, EXERNET (RED2022-134800-T; EXP 99828).

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The REBOTA-Ex parallel-group RCT (part of the iBoneFIT project) was approved by the Ethics Committee on Human Research of the Regional Government of Andalusia (Reference: 4500, December 2019), followed the ethical guidelines of the Declaration of Helsinki (revised version 2013), and was registered on isrctn.com (Reference: isrctn61195625, April 2, 2020).

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