Getty Images This guy is really going for that 9% bump in pay.

We don’t need a study to tell us that working out is good for us. But showing us that regular exercise is linked to higher salaries is a different matter.

In a new study published in the June issue of the Journal of Labor Research, researchers have found that employees who regularly exercise earn 9% more than their lazier counterparts.

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This sort of finding isn’t completely new. Previous studies have shown very similar things, but it’s often been difficult to determine whether there’s true causation. It could simply be that those who exercise also are more disciplined at work. Other studies have found a correlation between the amount of time employees exercise and their salary. But now there seems to be a stronger link found between earnings and exercise.

In this latest study, researcher Vasilios Kosteas of Cleveland State University scored each subject on how well they fit the profile of a regular exerciser. He then compared only similar individuals, some of whom didn’t exercise, and found that those who actually did earned more — 9% more.

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Other studies have shown the flip side: that people who are not in good shape tend to make less money. A 2007 study, for example, found that women who were obese earned, on average, 18% less than those who weren’t. Those who were overweight also had 25% less family income.

The latest study defined “regular exercise” as working out at least three hours a week. Considering that the average hourly wage in the U.S. is $23.41, the time workers spend at the gym is valued at $70.23 — but the extra pay the exercising employee receives is $84.28, about 20% more than the value of the time spent at the gym.

So even though a lot of people ending up wasting their memberships, maybe your monthly gym pass is worth it after all.