A study published in The Lancet has found that globally, one in 12 deaths could be prevented with 30 minutes’ worth of physical activity, five days a week

But it may be tricky for many to achieve, no matter the health benefits: the study found that only people who were able to build physical activity into their job, transport of housework were able to manage high levels of exercise.

The largest study of physical activity, tracking 130,000 people in 17 countries, found that this amount of exercise is associated with a reduced risk of death and cardiovascular disease.

Being highly active (750 minutes a week) is associated with an even greater reduction, and the authors found that this was more achievable for those who built physical activity into their day through active transport, job type, or housework.

The study confirms on a global scale that physical activity is associated with a lower risk of mortality and cardiovascular disease (including death from cardiovascular disease, heart attack, stroke, or heart failure), irrespective of a person’s home country, other risk factors for disease, the type of physical activity and whether the activity is for leisure or if it is taken as part of daily transport, at work, or housework.

It is estimated that around 23% of the world’s population falls short of the 150 minutes of moderate-intensity aerobic physical activity weekly, plus muscle-strengthening exercise at least twice a week, which is recommended by the WHO.

“Meeting physical activity guidelines by walking for as little as 30 minutes most days of the week has a substantial benefit, and higher physical activity is associated with even lower risks,” says lead author Dr Scott Lear, Professor of Simon Fraser University’s Faculty of Health Sciences and Pfizer/Heart & Stroke Foundation Chair in Cardiovascular Prevention Research at St. Paul’s Hospital in Canada.

“The affordability of other cardiovascular disease interventions, such as generic drugs and consuming fruits and vegetables, are often beyond the reach of many people in low-income and middle-income countries.

“However, physical activity represents a low cost approach to preventing cardiovascular disease, and our study provides robust evidence to support public health interventions to increase all forms of physical activity in these regions.”

Of the 10,6970 people who met the activity guidelines, 3.8% developed cardiovascular disease, compared to 5.1% of people who did not (23549 people).

Risk of mortality was also higher for people who did not meet the recommended amount of activity – 6.4% compared to 4.2% for people who met guidelines.

The authors say the findings suggest that, if the entire population met physical activity guidelines, 8% of deaths (equivalent to around one in 12 cases) and 4.6% of cardiovascular disease cases (almost one in 20 cases) could be prevented.

If the entire population was highly active (completing more than 750 minutes of physical activity a week), 13% of deaths (around one in eight cases) and 9.5% of cardiovascular disease cases (around one in 10) could be prevented.

Overall, almost a fifth of people in the study (18%, 23631 people) did not meet the physical activity guidelines, but almost half (44%, 57868 people) were highly active.

Physical activity as transport, occupation or housework was the most common form of physical activity, across all regions (ranging from 437 to 574 minutes per week).

While physical activity in leisure time was common in high-income countries (an average of 130 minutes per week), it was rare in other regions (25 minutes a week in lower-middle income countries and no time spent in this way in upper-middle- and low-income countries).

Overall, the more activity a person did the lower their risk of mortality and cardiovascular disease – with the study finding no ceiling effect on the association, and no risks associated with extremely high levels of physical activity (more than 2500 minutes per week, up to 17 times the physical activity guideline amount).

The authors recommend building physical activity into one’s daily lifestyle to achieve higher levels and reduce risk as much as possible, rather than using exercise as a leisure activity.

“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. This reflects the challenge of trying to be highly active during limited daily leisure time outside of work and domestic duties,” says Dr Lear.

Professor Ken Nosaka, the Director of Exercise and Sports Science in the School of Medical and Health Sciences, Edith Cowan University, says that it’s vital for stakeholders to ask how people are to achieve these exercise levels.

“It has been well documented that a lack of physical activities is the main cause of mortality, and the study in The Lancet confirms this, thus it is nothing very new,” he says.

“However, the study is admired for the large sample size; more than 130,000 participants from 17 different countries with different economic levels. 

“The authors state that the results of the study provide robust evidence to support public health interventions to increase all forms of physical activity. 

“So, one of the obvious questions is ‘how’.

“I assume that most people already know the importance of physical activities for health and wellbeing, but not many people actually meet the recommended amount (e.g., 150 min of moderate exercise per week),” says Prof Nosaka. 

“Thus, it is important to know why people do not respond to these kinds of messages based on research, and why people remain physically less active.

“We need to know more on how exactly we can increase physical activity.”