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

BACKGROUND: Exercise 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. METHODS: We 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 (