Exercise Effects on Bone Mineral Density in Men

Area of Science:

• Exercise science
• Bone metabolism
• Gerontology

Background:

• Evidence for exercise's positive impact on bone mineral density (BMD) is well-established in postmenopausal women, but remains limited in men.
• Potential reasons for limited evidence in men include a scarcity of studies and significant variability in study designs and participant characteristics.
• A need exists for a systematic evaluation of exercise interventions on BMD in men, employing rigorous eligibility criteria to clarify its effects.

Purpose of the Study:

• To conduct a systematic review and meta-analysis to evaluate the effect of exercise on bone mineral density (BMD) changes in men.
• To establish rational eligibility criteria for including relevant studies in the analysis.
• To synthesize findings from controlled trials to determine the impact of exercise on BMD in adult males.

Main Methods:

• A comprehensive literature search was performed across six electronic databases up to March 15, 2021.
• Included studies were controlled trials of at least six months duration, assessing areal BMD changes in men over 18 years old without relevant medical conditions or therapies affecting bone metabolism.
• Outcomes focused on standardized mean differences (SMD) in BMD for the lumbar spine (LS) and femoral neck (FN).

Main Results:

• Twelve studies comprising 16 exercise and 12 control groups were analyzed.
• The pooled meta-analysis revealed a significant, albeit low, effect of exercise on BMD, with SMD = 0.38 (95%-CI: 0.14-0.61) for LS and SMD = 0.25 (95%-CI: 0.00-0.49) for FN.
• Low to moderate heterogeneity was observed between trials. Evidence of small study publication bias was noted for LS-BMD but not FN-BMD.

Conclusions:

• This systematic review and meta-analysis provides further evidence supporting a low but significant positive effect of exercise on bone mineral density (BMD) in men.
• Subgroup analyses based on study length, exercise type, and methodological quality did not reveal significant differences in outcomes.
• Currently, specific exercise recommendations for optimizing BMD in male populations cannot be definitively provided due to the existing data.