PurposeThis study aimed to quantify the dose–response association and the minimal effective dose of leisure-time physical activity (PA) to prevent mortality and cardiovascular disease in adults with type 2 diabetes. MethodsCross-country comparison of 2 prospective cohort studies including 14,913 and 17,457 population-based adults with type 2 diabetes from the UK and China. Baseline leisure-time PA was self-reported and categorized by metabolic equivalent hours per week (MET-h/week) according to World Health Organization recommendations: none, below recommendation (>0–7.49 MET-h/week); at recommended level (7.5–14.9 MET-h/week); above recommendation (≥15 MET-h/week). Mortality and cardiovascular disease data were obtained from national registries. ResultsDuring a median follow-up of 12.4 and 9.7 years, in the UK and China cohorts, repectively, higher levels of leisure-time PA were inversely associated with all-cause (1571 and 2351 events) and cardiovascular mortality (392 and 1060 events), mostly consistent with a linear dose–response relationship. PA below, at, and above recommendations, compared with no activity, yielded all-cause mortality hazard ratios of 0.94 (95% confidence interval (95%CI): 0.79–1.12), 0.90 (95%CI: 0.74–1.10), and 0.85 (95%CI: 0.70–1.02) in British adults and 0.87 (95%CI: 0.68–1.10), 0.88 (95%CI: 0.74–1.03), and 0.77 (95%CI: 0.70–0.85) in Chinese adults. Associations with cardiovascular mortality were more pronounced in British adults (0.80 (95%CI: 0.58–1.11), 0.75 (95%CI: 0.52–1.09), and 0.69 (95%CI: 0.48–0.97)) but less pronounced in Chinese adults (1.06 (95%CI: 0.76–1.47), 1.01 (95%CI: 0.80–1.28), and 0.79 (95%CI: 0.69–0.92)). PA at recommended levels was not associated with lower rates of major adverse cardiovascular events (2345 and 4458 events). ConclusionLeisure-time PA at the recommended levels was not convincingly associated with lower mortality and had no association with risk of major adverse cardiovascular events in British or Chinese adults with type 2 diabetes. Leisure-time PA above current recommendations may be needed to prevent cardiovascular disease and premature mortality in adults with type 2 diabetes.