How much exercise per week lowers your risk of death?
Even a quarter-hour of exercise per day makes a measurable difference; the greatest gain comes from the step between doing nothing and doing something, and those who also add strength training do best.
As little as 15 minutes of moderate exercise per day is associated with a 14% lower chance of dying and a life expectancy that is on average three years longer, compared with people who do nothing at all. This comes from a Taiwanese study of more than 400,000 people followed over an average of eight years. Every additional quarter-hour per day on top of that minimum amount was linked to a further 4% reduction in mortality risk.
The greatest health gain per extra minute comes from the transition between doing almost nothing and doing something. People who concentrate all their exercise into one or two sessions at the weekend but still meet the guideline benefit just as much as someone who spreads it neatly across the week: roughly 30% lower mortality risk compared with completely inactive people. Even exercising below the official guideline of 150 minutes per week is already associated with 20% lower mortality. It is therefore not about the perfect distribution, but about the total.
The ceiling of the benefit lies at around three to five times the recommended amount (450 to 750 minutes of moderate exercise per week), which corresponds to approximately 39% lower mortality risk. Beyond that point no additional gain could be measured, but no harm either, even at ten times the guideline.
People who combine both aerobic exercise and muscle-strengthening activities gain the most: together this is associated with 40% lower mortality risk. Aerobic training alone already delivers 29% benefit, and strength exercises alone 11%. The combination therefore matters.
Sitting a great deal is an independent risk factor, separate from how much you exercise. People who sit the most face more than 2.5 times the mortality risk of those who sit the least. Sitting less and moving more therefore reinforce each other.
This answer is based on several large studies in which participants were followed for many years, including a study of more than 660,000 participants and a pooled analysis of eight studies with objectively measured activity data from more than 36,000 people. The association between more exercise and lower mortality risk is strikingly consistent across all these studies, but they are always associations: it is plausible, though not definitively proven, that more exercise is the cause of the longer life. The evidence for sedentary behaviour is also strong and independent, which lends additional weight to the findings.