Just a half-hour of physical activity a day could prevent millions of early deaths and cases of heart disease worldwide, a new study says.

“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,” said lead author Scott Lear.

Lear is a professor in the faculty of health sciences at Simon Fraser University in British Columbia, Canada.

He and his colleagues analysed survey responses from more than 130000 people aged 35-70 in 17 countries. Participants were asked about their levels of physical activity, then they were followed for nearly seven years.

The researchers concluded that 1 in 20 cases of heart disease and 1 in 12 premature deaths could be prevented if everyone met World Health Organisation guidelines. WHO recommends that adults do at least 150 minutes of moderate-intensity exercise a week.

Beneficial activity includes household chores, on-the-job movement or walking to work.

Of those who met the activity guidelines, 4% developed heart disease, compared with 5% of people who did not. Odds for early death were also higher for people who did not meet the recommended amount of activity - 6% versus 4%.

And more activity yielded greater benefits, the study found. If everyone got more than 750 minutes of physical activity a week, 13% of early deaths and about 10% of heart disease cases could be prevented, according to the study.

How did people do in terms of exercise? The study found that 18% of people did not meet the physical activity guidelines, but 44% were highly active.

The results were published in The Lancet this month.

“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,” Lear said in a journal news release.

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

“Cardiovascular disease is known to have devastating effects on individuals and families. In low-income and lower-middle-income countries, cardiovascular disease can push people to below the poverty line,” Dr Shifalika Goenka wrote in an accompanying editorial.

“Creating a physical, social and political environment where physical activity in daily living is desirable, accessible and safe should be a developmental imperative,” said Goenka, who is with the Indian Institute of Public Health in Delhi.

* You’ve probably heard that you need to get at least 150 minutes of moderate exercise every week. But a study published in the Journal of Applied Physiology suggests a mix of different types of exercise brings better results than adding more quantity.

That’s important if you spend hours at the gym, but focus solely on strength training or pounding the treadmill.

Researchers at Skidmore College in New York compared the effects of different exercise regimens. Participants got the most benefits from a programme that included resistance, cardio, interval training and stretching, along with eating moderate amounts of protein throughout the day.

The theory is that this blend addresses more of your body’s needs.

Give these suggestions a try:

Cardio 5 times a week with interval training on 3 sessions.

Strength training 2 to 3 times a week but not on consecutive days.

Stretching/flexibility exercises 2 to 3 times a week. - New York Times