A new study suggests that those younger than 60 who spend their days sedentary (which includes time spent on the internet, watching television, or reading) and minimal physical activity have a higher risk of stroke than those who are more physically active.

The study’s findings were published in the journal ‘Stroke,’ by the American Stroke Association, which is a branch of the American Heart Association.

According to AHA statistics, US adults spend an average of 10.5 hours a day connected to media such as smartphones, computers or television watching, and adults ages 50 to 64 spend the most time of any age group connected to media.

Additionally, data indicate that stroke-related mortality among persons 65 years and older dropped in 2010. Stroke death appears to be increasing among younger persons, ages 35 to 64 years, increasing from 14.7 deaths per 100,000 adults in 2010 to 15.4 deaths per 100,000 adults in 2016.

According to a previous study, the more time adults spend sedentary, the greater their risk of cardiovascular disease, including stroke, and roughly 9 out of 10 strokes are caused by modifiable risk factors such as sedentary behaviour.

“Sedentary time is increasing in the United States and Canada,” said the study author.

“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.”

The researchers analyzed health and lifestyle data from 143,000 persons without a history of stroke, heart disease, or cancer who participated in the Canadian Community Health Survey between 2000 and 2012.

The researchers monitored the patients for an average of 9.4 years (until Dec. 31, 2017) and identified strokes using hospital records.

They examined the amount of time spent each day on leisure sedentary activities (computer use, reading, and watching television) and classified them as follows: less than four hours per day; four to less than six hours per day; six to less than eight hours per day; and eight hours or more per day.

Additionally, they classified physical activity into quartiles, or four equal categories, with the lowest quartile being the least physically active and equating to taking a ten-minute walk everyday.

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

Adults should engage in at least 150 minutes, or 2.5 hours, of moderate-intensity physical exercise per week, according to the American Heart Association.

A review of the study’s participants revealed the following:

• Over an average of 9.4 years, 2,965 strokes occurred throughout the follow-up period. Nearly 90% of them were ischemic strokes, the most common type of stroke, which occurs when a blood vessel supplying the brain is blocked.

• The average daily sedentary time spent in leisure was 4.08 hours for all participants. Individuals aged 60 and younger spent an average of 3.9 hours per day in sedentary leisure. For those aged 60 to 79, the average daily sedentary time was 4.4 hours, and for those aged 80 and above, it was 4.3 hours.

• Adults 60 years and younger who had low physical activity and reported eight or more hours of leisure sedentary time a day had a 4.2 times higher risk of stroke compared to those reporting less than four hours of daily leisure sedentary time.

• The most inactive group — those reporting eight or more hours of sedentary time and low physical activity — had 7 times higher risk of stroke compared to those reporting less than four hours of sedentary time a day and higher levels of physical activity.

“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,” said the lead author.

“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 emphasise 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.”

A key drawback of the study’s findings is that participants were not asked about occupation-related sedentary time; this could imply that sedentary time is underreported among persons who work at desk jobs, for example.