We are told leisure activities like walking the dog or gardening can help decrease stroke risk by as much as 30%. Without question, some exercise is better than none. Some activities such as walking are recommended as having universal ‘positives.’ However, many messages give different recommendations, and, at worst, conflicting information. How much exercise is enough?
While most fitness guidelines focus on an ideal amount of physical activity per day for good health, there is a study that indicates that even low levels of physical activity are an improvement over doing nothing at all. The World Health Organization’s 2020 guidelines on physical activity emphasize the message: “some physical activity is better than none.”
“[The study] seems to be in line with other research that’s been published recently that shows that even low levels of physical activity can have tremendous benefits in terms of overall health and affecting mortality,” Dr. Michael Fredericson, Director of the PM&R Sports Medicine and co-director of the Stanford Center on Longevity at Stanford Medicine. He wasn’t affiliated with the research.
In the study, published in March 2022, in BMJ Journal of Neurology, Neurosurgery & Psychiatry, scientists performed a meta-analysis on 15 study articles after reviewing more than 3,000 studies on “leisure-time physical activity,” a catch-all term for any kind of physical activity, no matter the intensity. It encompasses a range of activities from gardening and walking to hiking, biking, and weightlifting.
An inactive or sedentary lifestyle is an established risk factor for many long-term conditions, including obesity, heart disease, type 2 diabetes and stroke. While that is well known, just how much physical activity someone needs to see health benefits isn’t as clear. In fact, the study points out that there isn’t even a consensus about the minimum amount of physical activity to decrease risk of stroke.
So, in a world where only one-in-four US adults meet physical activity guidelines, it’s understandable why researchers would want to know what the effects of doing even the bare minimum amount of exercise are on serious outcomes like stroke.
There is a clear signal from across 15 previously published articles that even minimal amounts of physical activity improved the risk of stroke, independent of age and sex.
Compared to individuals who did no leisure-time physical activity whatsoever, those who did even small amounts reduced their risk of stroke by between roughly 10-30%.
The study also found confirmatory results when looking at specific kinds of stroke outcomes. For ischemic stroke, the most common type of stroke, which is caused by an obstruction in a vessel supplying blood to the brain, individuals who demonstrated low levels of physical activity had a 13% reduction in risk compared to those with none.
Results were similar for haemorrhagic stroke, a less common form of stroke that occurs when a blood vessel bursts and begins to bleed in the brain. In this case, low levels of physical activity resulted in a 16% risk reduction compared to no physical activity.
What to know about physical activity
Part of the difficulty of assessing the health benefits of physical activity is its subjective nature: what is “moderate” for one person could be “intense” for another. So, when the researchers set out to do their review, they found differences in how prior studies categorized levels of exercise.