By now most people are probably on board with the idea that exercise is good for the body and brain. It reduces the risk of major health problems, increases psychological well-being, and even lowers the risk of death. But a new study offers some striking calculations about just how beneficial exercise is.

Researchers have calculated how many years exercise may add to your lifespan, which makes the effect of being active a little less murky and makes the importance of becoming more active that much clearer.

What’s particularly interesting is that these findings were true for everyone, no matter their body type, sex, or race. Normal weight, overweight, or obese people all derived a benefit the exercise they got.

In a large-scale review, the authors looked at data from 650,000 people over 10 years. The participants' activity levels were correlated with their risk of mortality (82,000 deaths were recorded) to determine the connection between various levels of activity and death risk. From this, the team could calculate how many years might be added to one’s life with varying levels of weekly exercise.

People who got just 75 minutes of moderate to vigorous activity (like brisk walking) per week had a 19% reduced risk of death. This, the researchers calculated, was equivalent to about 1.8 years added to one’s life, compared to people who did not exercise at all. For people who got even more activity in – 150 minutes per week, which is the amount recommended by organizations like the CDC – the added life expectancy was about 3.4 years. And according to senior author I-Min Lee, getting 450 minutes of activity per week would correlate to about 4.5 years of extended life.

What’s particularly interesting is that these findings were true for everyone, no matter their body type, sex, or race. Normal weight, overweight, or obese people all derived a benefit the exercise they got, but, perhaps not surprisingly, the advantage was the greatest for normal weight people who exercised for at least the recommended amount of time per week. Normal weight people who log about 150 minutes of activity per week could add around 7.2 years to their lives, compared with obese people who were not active.

As with most studies looking at relationships between behaviors (here, exercise) and health benefits over time, causation can’t be proven. One can only demonstrate a correlation between exercise and longevity. Still, the study looked at a vast amount of data, which helps make a convincing case that exercise is strongly related to life expectancy. For those of us who are a bit half-hearted about getting physical, this study adds a nice jolt of reality. Exercise really can make a difference – it’s just a matter of getting out there and doing it.

The study was carried out by a team at Brigham and Women's Hospital and the National Cancer Institute, and published in the journal PLoS Medicine.