MedicalResearch.com Interview with:
Michelle N. McDonnell, PhD
Division of Health Sciences
International Centre for Allied Health Evidence
University of South Australia
Adelaide, SA 5001 Australia.
MedicalResearch.com: What are the main findings of the study?
Dr. McDonnell: In this study, we asked people how many times a week they engaged in intense physical activity, enough to work up a sweat. People responded that they were physically active 0, 1-3 or 4 or more times a week. When we followed up these people for several years, those who did not do any vigorous exercise were 20% more likely to have a stroke, compared to those who exercised four or more times a week. However, when we adjusted these results for other risk factors, this attenuated the effect down to 14% which was not statistically significant. We also noticed that people who exercised four or more times a week had less hypertension (high blood pressure), were less likely to be obese and less likely to have
diabetes. Each of these things on their own reduces your risk of stroke, so when we adjust for that the association between physical activity and stroke is weaker (20% to 14%). So physical activity seems to have an effect on stroke risk by improving these other risk factors.