A study of people living in 17 wealthy and less wealthy nations has found that all forms of physical activity, be it working out in the gym, walking to work, or doing housework, reduces deaths and heart disease risks.
In a paper published in The Lancet, the researchers describe how the Prospective Urban and Rural Epidemiological Study (PURE) study followed nearly 131,000 people in 17 countries over 7 years.
The study also found that a high amount of exercise, totaling 750 minutes each week, was linked to the greatest benefit.
The team notes that this amount of exertion was more achievable for people who incorporated exercise as part of daily life, such as through "active transport," because of their job, or from doing household chores.
The finding confirms much of what has already been discovered from research done in wealthy nations. But those studies have tended to focus on leisure time activity.
The PURE study, which is the largest of its kind, is significant because it includes middle- and low-income countries and does not focus solely on leisure time.
"If everyone was active for at least 150 minutes per week, over 7 years," says principal investigator Prof. Salim Yusuf, director of the Population Health Research Institute at McMaster University in Ontario, Canada, "a total of 8 percent of deaths could be prevented."
People not meeting exercise guidelines
Guidelines published by the World Health Organization (WHO) advise that people aged 18 to 64 years to do two types of exercise every week: aerobic and muscle-strengthening.
For aerobic exercise, the guidelines recommend at least 150 minutes of moderate physical activity spread over the week - for example, 30 minutes per day on 5 days of the week. The advice on muscle-strengthening exercise is that it should be performed at least twice each week.
The guidelines for the United States are very similar. But estimates of global physical activity levels suggest that nearly a quarter (23 percent) of people are not meeting the recommended levels.
In the U.S., the figure is much higher, with estimates suggesting that most adults (around 79 percent in 2014) are not meeting the recommended levels of physical activity.
In their study paper, the authors note that cardiovascular disease is the "leading cause of death worldwide and a major economic global burden."
Furthermore, although rates of death due to cardiovascular disease have fallen in wealthy nations, global mortality from this cause has actually increased by 41 percent over the period 1990 to 2013, "largely driven by rises in low-income and lower-middle-income countries."
Sufficient activity reduced deaths
For the PURE study, 130,843 participants aged between 35 and 70 years, and living in either urban or rural communities in 17 countries around the world, filled in questionnaires.
The questionnaires asked them about their weekly exercise level and other characteristics, such as medical history, lifestyle, income status, weight, height, and blood pressure.
The researchers followed the participants for 6.9 years and recorded information on cardiovascular disease and death. The cardiovascular data allowed them to note specific events, such as heart attacks, strokes, heart failure, and deaths from cardiovascular disease.
The 17 countries taking part in the study were: Argentina, Bangladesh, Brazil, Canada, Chile, China, Colombia, India, Iran, Malaysia, Pakistan, Poland, South Africa, Sweden, Turkey, the United Arab Emirates, and Zimbabwe.
The researchers found that compared with people who did not meet the recommended levels of physical activity, the risk of death from any cause was 28 percent lower and the risk of heart disease was 20 percent lower in those who did.
They also found that the reductions were the same regardless of the type of physical activity that people did.
For people doing at least 750 minutes per week of recommended physical activity, the reduction in risk of death was 36 percent.
However, the team notes that fewer than 3 percent of participants achieved this level of exertion during leisure time, compared with 38 percent who achieved it while commuting, having physically active jobs, doing housework, or through another non-leisure activity.
"In low-income and lower-middle-income countries," notes Dr. Shifalika Goenka, of India's Centre for Chronic Disease Control, "cardiovascular disease can push people to below the poverty line."
She adds, in a linked editorial, "Promotion of physical activity, active transport, and active living by means of interventions contextualized to culture and context will have powerful and long-lasting effects on population health and developmental sustainability."
"For low- and middle-income countries where having heart disease can cause a severe financial burden, physical activity represents a low-cost approach that can be done throughout the world with potential large impact."
Prof. Salim Yusuf