Moderate exercise lowers death risk, study finds

Moderate physical activity per day may lower one’s risk of premature death, according to an analysis published in the British Journal of Sports Medicine. Researchers analyzed data from nearly 200 studies involving more than 30 million participants from around the world, who self-reported their activity levels for at least three years. The team then looked at the association between physical activity and 22 distinct health outcomes, including 14 types of cancer, making it one of the largest analyses of its kind.

The results indicated that people who were moderately active for 75 minutes per week — meaning they engaged in activities like hiking, walking briskly, cycling to work or playing actively with their children — had lower risks of overall mortality, heart disease, stroke and various cancers relative to people who were not active.

The researchers estimated that one in 10 premature deaths, defined by the World Health Organization as deaths between ages 30 and 70, tallied in their analysis could have been prevented if everyone had engaged in moderate physical activity for 75 minutes per week. That is half the amount of exercise recommended by the WHO and the Centers for Disease Control and Prevention. Both say adults should get at least 150 minutes of moderate physical activity per week. Globally, one in four adults don’t meet these recommendations. In the US, fewer than half of adults do.

“Many people think that to get moderate levels of physical activity, or to meet these recommended levels, they need to go to structured sessions of exercise or really do extra-strenuous activities, when in reality, activities that we do in our routines could also be very beneficial,” Leandro Garcia, an author of the analysis and a public health lecturer at Queen’s University Belfast said. But Amanda Paluch, an epidemiologist and kinesiologist at the University of Massachusetts Amherst who was not involved in the new analysis, cautioned against thinking of 11 minutes as a minimum or maximum daily target. “This is a very broad, generalized number, so putting a lot of stock in that specific number would be a little challenging,” Paluch said. “We are finding that lower than 10,000 steps per day, there’s still significant benefit,” said Kelly Evenson, an epidemiology professor at the University of North Carolina at Chapel Hill who co-authored that study with Paluch.

Their results suggested that people with a median of around 6,000 to 11,000 daily steps had a 50 to 60 per cent lower risk of death relative to those with a median of around 3,500 steps per day.

“We’ve seen across age that it’s never too late to start being active and that benefits accrue pretty quickly. There’s not an age in which physical activity isn’t useful,” Evenson said.

All three experts interviewed agreed that the WHO and CDC recommendations are still the ideal thresholds for physical activity. “Physical activity works on nearly every cell of the body,” Paluch said. “It could influence things like inflammation, for example, which is associated with cancer.”