title: Frequent physical activity may not reduce vascular disease risk as much as moderate activity: large prospective study of women in the United Kingdom.
abstract: BACKGROUND
  Although physical activity has generally been associated with reduced risk of vascular disease, there is limited evidence about the effects of the frequency and duration of various activities on the incidence of particular types of vascular disease.
  
  
  RESULTS
  In 1998, on average, 1.1 million women without prior vascular disease reported their frequency of physical activity and many other personal characteristics. Three years later, they were asked about hours spent walking, cycling, gardening, and housework each week. Women were followed by record linkage to National Health Service cause-specific hospital admissions and death records. Cox regression was used to calculate adjusted relative risks for first vascular events in relation to physical activity. During an average of 9 years follow-up, 49,113 women had a first coronary heart disease event, 17,822 had a first cerebrovascular event, and 14,550 had a first venous thromboembolic event. In comparison with inactive women, those reporting moderate activity had significantly lower risks of all 3 conditions (P<0.001 for each). However, women reporting strenuous physical activity daily had higher risks of coronary heart disease (P=0.002), cerebrovascular disease (P<0.001), and venous thromboembolic events (P<0.001) than those reporting doing such activity 2 to 3 times per week. Risks did not differ between hemorrhagic and ischemic stroke, or between venous thromboembolic events with or without pulmonary embolism.
  
  
  CONCLUSIONS
  Moderate physical activity is associated with a lower risk of coronary heart disease, venous thromboembolic event, and cerebrovascular disease than inactivity. However, among active women, there is little to suggest progressive reductions in risk of vascular diseases with increasing frequency of activity.
authors: From Cancer Epidemiology Unit, University of Oxford, Oxford, United Kingdom. miranda.armstrong@ceu.ox.ac.uk.
authors: Miranda E G
authors: ME
authors: Armstrong
authors: From Cancer Epidemiology Unit, University of Oxford, Oxford, United Kingdom.
authors: Jane
authors: J
authors: Green
authors: From Cancer Epidemiology Unit, University of Oxford, Oxford, United Kingdom.
authors: Gillian K
authors: GK
authors: Reeves
authors: From Cancer Epidemiology Unit, University of Oxford, Oxford, United Kingdom.
authors: Valerie
authors: V
authors: Beral
authors: From Cancer Epidemiology Unit, University of Oxford, Oxford, United Kingdom.
authors: Benjamin J
authors: BJ
authors: Cairns
mesh_terms: D002318:Cardiovascular Diseases / Q000453:epidemiology*; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology
keywords: coronary disease; exercise; stroke; venous thromboembolism