According to Steven Hooker, the study's lead author, fitness has a protective effect, regardless of other stroke risk factors, including family history, raised cholesterol and a high body mass index.
Researchers in this study looked at more than 60 000 people who participated in the Aerobics Centre Longitudinal Study between 1970 and 2001 in Dalla, Texas. Participant, aged between 18 and 100 years, did not have cardiovascular disease when they entered the study. During that time 863 people had strokes.
At the start of the study each participant was tested for cardiorespiratory fitness (CRF) using a treadmill test. Men in the top 25% of CRF had a 40% lower relative risk of stroke compared to men in the bottom 25%. Among women those with a higher level of CRF had a 43% lower relative risk of stroke compared with those in the lowest fitness level.
The overall risk of stroke dropped significantly at moderate levels of CFR, with the protective effect remaining nearly unchanged through higher fitness levels. According to researchers, this moderate fitness level corresponds to 30 minutes of aerobic exercise, such as brisk walking, five days a week. This is yet another study that suggests that keeping fit is the best way to remain healthy.
