Effects of different types of exercise over 24 weeks on bone mineral density in postmenopausal women: A systematic review with pairwise and network meta-analysis of randomized controlled trials.

backgroundExercise is a pivotal non-pharmacological strategy to prevent bone loss and osteoporosis in postmenopausal women (PMW). While various exercise modalities, such as mind-body (MBEx) (e.g., Tai Chi, yoga, and Pilates), resistance (Re), aerobic (Ae), impact (Im), and multimodal (Multimodal) exercise, can effectively improve bone mineral density (BMD), their effects differ across multiple skeletal sites. This study aimed to compare the effects of different exercise modalities on BMD at multiple skeletal sites in PMW.

methodsWe systematically searched PubMed, Web of Science, Cochrane Library, and Embase (July 1989 to June 2025) for randomized controlled trials testing exercise interventions lasting ≥24 weeks on BMD in PMW or healthy women aged ≥60 years. Studies with participants taking hormone replacement therapy, bone-affecting medications, or major comorbidities were excluded. BMD was measured by dual-energy X-ray absorptiometry or dual-photon absorptiometry. The risk of bias was assessed using the Cochrane RoB 2 tool. A meta-analysis was performed using a random-effects model. Subgroup analyses were conducted based on intervention duration (<52 weeks vs. ≥52 weeks) and baseline BMD status (normal vs. low bone mass). Meta-regression was performed to examine time-related trends.

resultsAmong 24,071 studies, 74 studies (5331 participants) were included. Results showed that MBEx combined with Re (MBEx_Re) was the most effective modality for improving BMD at the lumbar spine, femoral neck, Ward's triangle, and total body. Multimodal showed benefits for total hip and femoral neck BMD, while MBEx, Re, Im, and Ae alone demonstrated site-specific effects. No significant effect was observed at the intertrochanter. Subgroup analyses revealed that interventions lasting ≥52 weeks produced more consistent and sustained improvements than shorter interventions. Meta-regression indicated a general decline in effect size over time at most skeletal sites. Exercise-induced BMD gains were comparable between PMW with normal and low BMD.

conclusionExercise interventions have site- and modality-specific effects on BMD in PMW. Combined exercise modalities, such as MBEx_Re and Multimodal, may offer superior benefits for improving BMD, while single modality interventions remain effective at specific sites. Longer intervention durations (≥52 weeks) appear to promote more consistent and sustained improvements. These findings offer clinically relevant guidance for tailoring exercise prescriptions in the prevention and management of osteoporosis. Incorporating combined modalities, particularly those that integrate strength, balance, and neuromuscular coordination, may offer superior benefits for bone health, which may positively contribute to reducing osteoporotic fractures.