Reduction in incident stroke risk with vigorous physical activity: evidence from 7.7-year follow-up of the national runners' health study.

Abstract

The purpose of this study was to assess the dose-response relationship between vigorous physical activity (running distance, km/d) and the participant-reported physician-diagnosed stroke. Age-adjusted survival analysis of 29 279 men and 12 123 women followed prospectively for 7.7 years. One hundred men and 19 women reported incident strokes. Per km/d run, the age- and smoking-adjusted risk for stroke decreased 12% in men (P=0.0007), and 11% in men and women combined (P=0.001), which remained significant when further adjusted for baseline diabetes, hypercholesterolemia, hypertension, and BMI (8% and 7% reduction per km/d run, respectively, P=0.03). Men and women who ran >or=2 km/d (ie, exceeded the recommended AHA/CDC and NIH guideline activity level) had significantly lower risk than those who ran less (P=0.05), and those who ran >or=4 km/d had significantly lower risk than those who ran 2 to 3.9 km/d (P=0.02). Men and women who ran >or=8 km/d were at 60% lower risk than those who ran <2 km/d (P=0.00). The risk for incident stroke is substantially reduced in those who exceed the guideline physical activity level, which cannot be attributed to less hypertension, diabetes, hypercholesterolemia, or body weight.