If you want to live longer, you might want to push yourself just a little harder during your next gym visit: a new study reveals that putting extra strain on your body when you exercise matters more than squeezing in another session.
Researchers from the University of Basel in Switzerland and the University of Leicester in the UK have shown the intensity of your exercise can be more important than the time spent engaging in physical activity.
The team amassed three years of fitness tracker information covering a total of 7,518 adults in the US, with mortality data logged for an additional four years after that.
Higher intensity physical activity was found to be associated with comparitively lower risk of an early death from all causes, but the difference was most noticeable when it came to cardiovascular disease – think strokes, artery disease, and other heart problems.
"Higher intensity stimulates the cardiovascular system more," says University of Basel sports scientist Fabian Schwendinger.
"This improves vascular function and cardiorespiratory fitness … the performance of the cardiovascular and respiratory systems."
Boosting the speed of your regular jogs, or taking the stairs instead of the lift are just two ways daily activity can be given a healthy boost. To take one example from the data, an extra 150 minutes of brisk walking during the week could reduce mortality risk by as much as 28 percent, the study reports. That's a significant benefit for not much extra effort.
The research chimes with previous studies that found greater intensity during exercising can have positive health effects, though the study also compared directly against the total duration of exercising.
"One of the great strengths of our study is that it included people with very different levels of fitness and health," says Schwendinger.
"This means that everyone, regardless of whether they are very athletic or inactive, can benefit from the knowledge that intensity reduces mortality."
The study authors also found that intense physical activity seems to be most beneficial when it's done in one session, rather than spread out over the day.
To be clear, more exercise of any intensity is helpful. What's more, there is such a thing as overdoing it. There will come a point when exercising harder won't give you any extra years on the end of your life, and may actually start doing damage to your body instead.
"It's not about people only living longer if they train extremely intensively, wear themselves out and are completely out of breath," says Schwendinger.
The research has been published in the European Journal of Preventive Cardiology.