Regular physical activity can reduce the risk of having a stroke, suggests study.
A stroke can occur when a blood vessel in the brain gets blocked. As a result, nearby brain cells will die after not getting enough oxygen and other nutrients.
A number of risk factors for stroke have been identified, including smoking, high blood pressure, diabetes and being inactive.
For this study, Michelle N. McDonnell, Ph.D., from the University of South Australia, Adelaide and her colleagues obtained data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study.
REGARDS is a large, long-term study funded by the NIH National Institute of Neurological Disorders and Stroke (NINDS) to look at the reasons behind the higher rates of stroke mortality among African-Americans and other residents living in the Southeastern United States.
"Epidemiological studies such as REGARDS provide an important opportunity to explore race, genetics, environmental, and lifestyle choices as stroke risk factors," Claudia Moy, Ph.D., program director at NINDS, said.
Over 30,000 participants supplied their medical history over the phone. The researchers also visited them to obtain health measures such as body mass index and blood pressure.
At the beginning of the study, the researchers asked participants how many times per week they exercised vigorously enough to work up a sweat.
The researchers contacted participants every six months to see if they had experienced a stroke or a mini-stroke known as a transient ischemic attack (TIA). To confirm their responses, the researchers reviewed participants' medical records.
The researchers reported data for over 27,000 participants who were stroke-free at the start of the study and followed for an average of 5.7 years. One-third of participants reported exercising less than once a week.
Study subjects who were inactive were 20 percent more likely to experience a stroke or TIA than participants who exercised four or more times a week.
The findings revealed that regular, moderately vigorous exercise, enough to break a sweat, was linked to reduced risk of stroke. Part of the protective effect was due to lower rates of known stroke risk factors such as hypertension, diabetes, obesity and smoking.
The study is published in the journal Stroke.