A one-year recreational cross-fit program enhances bone health in young inactive males: A novel intervention study.

BACKGROUND

As far as we are aware, the influence of Cross-Fit training on bone health indicators in young men has not yet been examined. Therefore, the primary objective of this randomized controlled trial (RCT) was to assess the effects of a one-year Cross-Fit training intervention on various bone-related outcomes including bone mineral content (BMC), bone mineral density (BMD), femoral neck geometry, and composite indices of femoral neck strength in a cohort of physically inactive young males.

METHODS

Forty healthy but inactive young men were initially recruited for the study, of whom 26 completed the intervention. Assessments included bone mineral content (BMC), bone mineral density (BMD), and hip structural parameters using dual-energy X-ray absorptiometry (DXA). Physical fitness was measured using standardized and validated tests. Participants were randomly divided into two groups: a Control Group (CG; n = 13) and a Cross-Fit Group (CFG; n = 13). The CFG engaged in supervised Cross-Fit sessions twice per week, each lasting approximately 60 min. Statistical analyses were performed using two-way repeated-measures ANOVA (two-way RM-ANOVA) followed by Holm-Sidak post-hoc tests for pairwise comparisons.

FINDINGS: There were significant group * time interactions in whole body (WB) BMC (p = 0.001), WB BMD (p = 0.035), femoral neck cross-sectional area (CSA) (p = 0.039), one-repetition maximum (1-RM) bench press (p < 0.001), 1-RM shoulder press (p < 0.001), 1-RM deadlift (p = 0.021), maximum oxygen consumption (VO2 max) (p = 0.04), vertical jump (p < 0.001) and lower limb muscular power (p = 0.01). In addition, WB BMC (p < 0.001), WB BMD (p < 0.001), femoral neck cross-sectional area (CSA) (p < 0.05), 1-RM bench press (p < 0.001), 1-RM shoulder press (p < 0.001), 1-RM deadlift (p < 0.001), vertical jump (p < 0.001) and lower limb muscular power (p < 0.001) significantly increased in the CFG but not in the CG.

INTERPRETATIONS: The findings of this study indicate that a one-year Cross-Fit training program effectively enhances whole-body bone mineral content, whole body bone mineral density, femoral neck cross-sectional area, and various physical performance indicators in physically inactive young men.

TRIAL REGISTRATION: OSF, July 9, 2025. Registration DOI: https://doi.org/10.17605/OSF.IO/EDRBQ "Retrospectively registered".