Research Progress in Mechanism of Exercise Combined with Nutritional Intervention in the Prevention and Treatment of Osteosarcopenia

With the intensification of population aging, osteosarcopenia (OS) has emerged as a significant degenerative disease that poses a considerable threat to the health of the elderly. It is characterized by the synergistic deterioration of progressive reduction in skeletal muscle mass and decline in bone density, which significantly increases the risk of fall, fracture, and all-cause mortality. Hormonal disorders, chronic inflammation, and the lack of mechanical stress during the aging process collectively result in an imbalance in muscle and bone metabolism, primarily by affecting the secretion of muscle-derived and bone-derived factors as well as muscle-bone interactions. Exercise and nutritional interventions have proven to be effective strategies for the prevention and treatment of OS. Aerobic exercise delays muscle aging and increases bone density by activating signaling pathways such as insulin-like growth factor-1 (IGF-1), adenosine 5’-monophosphate (AMP)-activated protein kinase (AMPK)/calcium/calmodulin-dependent protein kinase Ⅱ (CaMKII) and Wnt1/β-catenin. Resistance exercise improves and maintains bone metabolic homeostasis, and promotes muscle protein synthesis by regulating the Fos/Fosb, mitogen-activated protein kinase and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathways. Whole-body vibration training and blood flow restriction training have emerged as exercise modalities to promote muscle generation and bone mineralization by modulating the AMPK/UNC-51 like autophagy activating kinase 1 (ULK1), forkhead box protein O (FoxO)/ peroxisome proliferator activated receptor γ coactivator-1α(PGC-1α), and IGF-1/growth hormone (GH) signaling pathways. Nutritional intervention strategies have demonstrated that proteins and their derivatives, such as creatine, facilitate muscle synthesis through the mTORC1 signaling pathway. Additionally, vitamin D₃ regulates bone metabolic balance via the retinoid X receptor (RXR)/VD receptor (VDR) signaling pathway, while calcium supplements and probiotics exert anti-inflammatory and bone-forming effects by modulating the gut-bone axis. This review systematically elucidates the synergistic mechanism of action of exercise and nutritional interventions in regulating muscle-bone metabolism, aiming to provide a theoretical basis and framework for the personalized prevention and treatment of OS and the development of precise nutritional strategies for this disease.