Just 30 minutes of moderate physical activity five days a week — a total of 150 minutes a week — has been linked to reduced risk of heart disease and death, according to a major international study published last week in the journal The Lancet.
And the risk drops even further as people increase their physical activity.
But most important, the study also found that a wide variety of physical activity — doing housework or walking to the bus stop or engaging in manual labor at the workplace — is beneficial for the heart.
In other words, you don’t have to train for a marathon or join a gym.
This isn’t the first study to show an association between regular physical activity and a reduced risk of heart disease. But earlier research was mostly conducted in high-income countries, where people engage in recreational exercise. The current study included people from lower-income countries, where exercising for leisure is less common but daily living involves considerable physical activity — on the job, in the home and just getting around from place to place.
The researchers wanted to see if such day-to-day activities could also benefit the heart.
Heart disease is a major global health concern. As background information in the study points out, it is the leading cause of premature death worldwide, and most of those deaths — 70 percent — occur in middle-income and low-income countries.
In recent decades, deaths from heart disease have been falling in the United States and in other high-income countries. They have been rising, however, in middle- and low-income countries — by 41 percent between 1990 and 2013.
The current study, known as the Prospective Urban Rural Epidemiologic (PURE) study, involved more than 130,000 people aged 35 to 70 from urban and rural areas in 17 countries: Canada, Sweden and the United Arab Emirates (high income); Argentina, Brazil, Chile, Poland, Turkey, Malaysia and South Africa (upper-middle income); China, Colombia and Iran (lower-middle income); and Bangladesh, India, Pakistan and Zimbabwe (low income).
None of the participants had heart disease at the start of the study.
The participants filled out a detailed questionnaire, which included questions about how much activity they did and whether it was recreational or nonrecreational (having to do with transportation, housework or a job).
The activity was categorized into three physical activity groups: low (less than 150 minutes of moderate physical activity a week), moderate (150-750 minutes of moderate activity a week) and high (more than 750 minutes of moderate activity a week).
Many health organizations, including the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) recommend that adults aged 18 to 64 do some kind of physical activity for at least 150 minutes a week.
The researchers followed the participants for seven years. The researchers tracked all heart-disease-related “events,” including heart attacks, strokes and heart failure. They also recorded deaths, from heart disease as well as from other causes.
An analysis of all the data revealed a strong association between heart disease and physical activity. Among the people who were physically active for at least 150 minutes a week, 3.8 percent developed heart disease within the seven years of the study. That compared to 5.1 percent of the people who did not meet that minimum level of activity.
People who did not meet the minimum amount recommended activity were also more likely to have died within the study period: 6.4 percent compared to 4.2 percent for people who did.
These risks and benefits were seen across all countries.
The researchers estimated that if everyone met physical activity guidelines, 8 percent of deaths (equivalent to around one in 12 cases) and 4.6 percent of heart disease cases (almost one in 20 cases) could be prevented.
They also estimated that if everyone became highly active (completing more than 750 minutes of physical activity a week), 13 percent of deaths (around one in 8 cases) and 9.5 percent of cardiovascular disease cases (around 1 in 10) could be prevented.
But becoming highly active requires more than doing an after-work run or workout at the gym.
“Our study found that high physical activity was only possible in people who completed physical activity as a form of transport, part of their job or through housework — with 37.9% people who acted in this way attaining this level of activity, compared to 2.9% who were only physically active in their leisure time,” said Scott Lear, the study’s lead author and a professor of health sciences at Simon Fraser University in Vancouver, Canada, in a released statement.
“This reflects the challenge of trying to be highly active during limited daily leisure time outside of work and domestic duties,” he added.
A major caveat
This study is observational, which means it can’t prove that physical activity was the direct reason people who exercised were less likely to develop heart disease. Furthermore, the study relied on people reporting their personal activity levels, and such reports can be inaccurate.
Still, the findings support those from many other studies on the topic — and they reinforce the idea that any type of physical activity is good for the heart.
“Increasing physical activity is a simple, widely applicable, low cost global strategy that could reduce deaths and CVD in middle age,” the study’s authors conclude.
FMI: You’ll find the study on The Lancet’s website. You’ll find information on how to incorporate more physical activity into your daily life on the National Heart, Lung and Blood Institute’s website.