What's the minimum amount of exercise we can do for maximum health and lifespan benefits?
New research, published in The Lancet, set out to answer this question.
World Health Organisation guidelines recommend a minimum of 30 minutes of "moderate-intensity aerobic physical activity" five days a week, but whether less exercise than the recommended 150 minutes a week and whether different types of exercise can have life expectancy and other health benefits is unclear.
So, the Canadian study tracked the exercise patterns and life expectancy of more than 130,000 adults from 17 different countries over the course of six to nine years.
Compared with those who did less than 150 minutes a week, people who exercised for 30 minutes a day had a reduced risk of heart disease and premature death in high-income, middle-income, and low-income countries.
In fact, the researchers suggest that 30 minutes of exercise a day could prevent one in 12 deaths and one in 20 cases of heart disease globally. It needn't be strenuous exercise either; active transport (i.e. walking to and from work), physical jobs and household chores made the cut.
Previous research has found that simply walking more leads to a remarkable reduction in the risk of heart disease, type 2 diabetes, some cancers, arthritis, depression, anxiety and insomnia and premature death from all causes.
Currently, about 60 per cent of the Australian adult population do not manage the recommended 30 minutes of exercise a day, a rate that hasn't shifted in the past 20 years, said Professor David Dunstan, the head of physical activity at the Baker Heart and Diabetes Institute.
"Movement [physical activity] is acknowledged as being the antidote to sitting – these findings clearly emphasise the importance of shifting the ever increasing number of people who do little or no physical activity to doing 'some' physical activity, since even low amounts of physical activity provides substantial benefit," Dunstan said.
"The study also showed the health benefit increased if people did higher levels of physical activity," said Professor Kevin Norton, from the School of Health Sciences at the University of South Australia.
Dr Brigid Lynch, a Senior Research Fellow at Cancer Council Victoria, said the research was "important" because it showed that informal activity as well as planned exercise helps all people.
"Physical activity was beneficial for individuals regardless of whether they were young or old, overweight or not, smokers or not, or had a pre-existing chronic disease or not," Lynch said.
"The message is that being physically active across the day, in a range of settings, has important health benefits for everyone."
While strength-based exercised is recommended for bone density, walking is the most popular physical activity of Australian adults. And, as it has been pointed out by the experts, it's free, easy and can be done almost anywhere.