title: Reduction in incident stroke risk with vigorous physical activity: evidence from 7.7-year follow-up of the national runners' health study.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Age-adjusted survival analysis of 29 279 men and 12 123 women followed prospectively for 7.7 years.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory, Donner Laboratory, Berkeley, CA 94720, USA. ptwilliams@lbl.gov
authors.forename: Paul T
authors.initials: PT
authors.lastname: Williams
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D040242:Risk Reduction Behavior; D012420:Running / Q000502:physiology*; D020521:Stroke / Q000517:prevention & control*; D016019:Survival Analysis