Low‐Intensity Physical Activity and Sarcopenia Risk in Aging Populations: A Nationally Representative Study From China

BACKGROUND: Sarcopenia is a major health concern in aging populations, particularly in China, which faces the world's largest demographic shift toward older age. Physical activity (PA) is a modifiable factor for sarcopenia prevention, but the role of activity intensity and dose remains uncertain. Evidence from Chinese cohorts is especially scarce. METHODS: We analyzed data from 6018 adults in the China Health and Retirement Longitudinal Study. Sarcopenia was defined using the 2019 Asian Working Group for Sarcopenia criteria. PA was self-reported and categorized into high- (HPA), moderate- (MPA), and low-intensity (LPA), as well as total PA. Logistic regression models estimated odds ratios for sarcopenia, and Cox regression assessed associations with 10-year all-cause mortality. Subgroup, sensitivity, and dose-response analyses were performed. RESULTS: At baseline, 19.0% of participants had sarcopenia. In unadjusted models, meeting total PA guidelines and engaging in LPA were associated with lower odds of sarcopenia. However, after full adjustment, these associations attenuated, while HPA was linked to higher sarcopenia risk. Dose-response analysis showed that 150-299 min of weekly LPA reduced sarcopenia risk by 51%. Long-term survival analysis indicated that ≥ 300 min of weekly PA significantly reduced 10-year mortality, even among individuals with sarcopenia. CONCLUSION: This study provides the first nationally representative evidence from China on the relationship between PA and sarcopenia. Findings emphasize that both PA volume and intensity composition matter, with moderate weekly PA dominated by LPA offering the greatest protection. Promoting feasible, sustainable activity should be prioritized in sarcopenia prevention strategies for older adults.