This meta-analysis investigates the relationship between physical activity and cognitive decline in nondemented subjects. The study included 15 prospective studies (12 cohorts) with a total of 33,816 participants followed for 1 to 12 years. The analysis showed that subjects who engaged in high levels of physical activity had a 38% reduced risk of cognitive decline (hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.54–0.70; P < 0.00001). Similarly, those with low-to-moderate levels of physical activity also had a 35% reduced risk of cognitive decline (HR 0.65, 95% CI 0.57–0.75; P < 0.00001). The results suggest that physical activity, regardless of intensity, is protective against cognitive decline in nondemented individuals. The study highlights the importance of physical activity in maintaining cognitive function, even in the absence of neurodegenerative diseases, and suggests that further research is needed to determine the optimal type, frequency, and intensity of exercise for preserving cognitive health.This meta-analysis investigates the relationship between physical activity and cognitive decline in nondemented subjects. The study included 15 prospective studies (12 cohorts) with a total of 33,816 participants followed for 1 to 12 years. The analysis showed that subjects who engaged in high levels of physical activity had a 38% reduced risk of cognitive decline (hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.54–0.70; P < 0.00001). Similarly, those with low-to-moderate levels of physical activity also had a 35% reduced risk of cognitive decline (HR 0.65, 95% CI 0.57–0.75; P < 0.00001). The results suggest that physical activity, regardless of intensity, is protective against cognitive decline in nondemented individuals. The study highlights the importance of physical activity in maintaining cognitive function, even in the absence of neurodegenerative diseases, and suggests that further research is needed to determine the optimal type, frequency, and intensity of exercise for preserving cognitive health.