A new study reveals that spending excess time doing leisurely, sedentary activities quadruples stroke risk in young adults. The risk is highest in sedentary people–those who spend eight or more hours per day engaged in little physical activity. Researchers define sedentary leisure time as any activity done sitting or lying down. This could include spending free time watching TV, using a computer or smartphone, or reading.

However, they found that increasing physical activity could reduce or eliminate the elevated stroke risk from excess sedentary time. Participants in the study who engaged in more physical activity had a lower risk of stroke, unsurprisingly. Researchers say that public health efforts to encourage more physical activity in adults younger than sixty could lower their stroke risk.

The research was published earlier this month in Stroke, a journal of the American Stroke Association, a division of the American Heart Association.

According to the AHA, US adults spend an alarming amount of time connected to devices each day. On average, adults spend 10.5 hours a day consuming media on smartphones, computers, or TVs. The data showed that adults aged 50 to 64 spend the most time using media out of all age groups. It also revealed that stroke-related deaths decreased in 2010 among adults 65 years and older.

However, stroke deaths among younger adults ages 35 to 64 have been increasing in the same time period. In 2010, 14.7 in every 100,000 adults of this age group died from a stroke compared to 15.4 per 100,000 in 2016.

The AHA believes that a dramatic increase in sedentary time is to blame. Prior research suggests that cardiovascular disease risk, including stroke, increases with more sedentary time. Modifiable risk factors such as a sedentary lifestyle contribute to nearly 90% of strokes.

Excess Sedentary Leisure Time Increases Stroke Risk in Young Adults

stroke risk
“Sedentary time is increasing in the United States and Canada,” said study author Raed A. Joundi, M.D., D.Phil., a stroke fellow in the department of clinical neurosciences at the Cumming School of Medicine at the University of Calgary in Canada. “Sedentary time is the duration of awake activities that are done sitting or lying down. Leisure sedentary time is specific to the sedentary activities done while not at work. It is important to understand whether high amounts of sedentary time can lead to stroke in young individuals, as a stroke can cause premature death or significantly impair function and quality of life.”

For the study, researchers analyzed the health and lifestyle of 143,000 adults with no history of stroke, heart disease, or cancer. They participated in the Canadian Community Health Survey in 2000, 2003, 2005, and 2007-2012. The research team studied the participants for an average of 9.4 years (until Dec. 31, 2017) and used hospital records to identify stroke events.

After reviewing the participants’ time spent each day in leisure sedentary activities, they organized the data into groups. The team divided leisure time into the following categories:

  • less than four hours per day;
  • four to less than six hours per day;
  • six to less than eight hours per day, and;
  • eight or more hours per day.

Researchers also categorized physical activity into quartiles or four equal categories. The lowest quartile corresponded with the least physically active participants. The physical activity of this group equated to going for a walk for ten or fewer minutes daily.

Joundi said this in the report:

“A walk of 10 minutes or less per day is lower than half of what the American Heart Association’s physical activity guidelines recommend.

The American Heart Association recommends adults engage in a minimum of 150 minutes, or two and a half hours, of moderate-intensity physical activity per week. This would mean going for a brisk walk for at least thirty minutes per day on average.

Key Findings From the Study That Links Stroke Risk to Sedentary Behaviors

  • During the nearly 10-year follow-up period, 2,965 strokes occurred. Ischemic strokes, the most common type of stroke, made up 90% of stroke events. These occur when blood flow through an artery supplying blood to the brain becomes blocked.
  • All participants had an average daily leisure sedentary time of 4.08 hours per day. Adults aged 60 and younger spent an average of 3.9 hours per day doing leisure activities. Adults ages 60 to 79 had an average of 4.4 hours, while adults 80 and older averaged 4.3 hours.
  • The stroke risk with 8+ hours of sedentary time was significantly higher only among adults aged 60 or younger who were the least physically active. They had a 4.2x higher stroke risk than adults who had less than four hours of daily leisure sedentary time.
  • The least active group had a seven times higher stroke risk than adults with less than four hours of sedentary time who had higher physical activity levels.

Joundi reported the following:

“Adults 60 years and younger should be aware that very high sedentary time with little time spent on physical activity can have adverse effects on health, including increased risk of stroke. Physical activity has a very important role in that it reduces the actual time spent sedentary, and it also seems to diminish the negative impact of excess sedentary time. Physician recommendations and public health policies should emphasize increased physical activity and lower sedentary time among young adults in combination with other healthy habits to lower the risks of cardiovascular events and stroke.”

Note that this study only included leisure sedentary time. Taking occupation-related sedentary time into account, it’s likely that participants spent much longer sitting each day. People who work desk jobs, for example, may want to pay extra attention to this study. After getting off work, exercising is probably the last thing on your mind, but it may help prevent a stroke.

stroke risk
Final Thoughts on a Study Showing How Too Much Leisure Time Increases Stroke Risk

Sadly, young people today have a higher stroke risk due to several factors, including a sedentary lifestyle. A new American Heart Association study found that excess sedentary time (eight or more hours per day) more than quadruples stroke risk in young adults. It’s even worse when comparing inactive adults to highly active adults – the risk increases by seven times.

This study proves the importance of being at least moderately physically active. Instead of watching a show or scrolling social media after work, go for a walk instead. It just might save your life.