In a 2012 research paper, Vasilios Kosteas, a Cleveland State University economist, found that people who regularly exercise earn roughly 6% – 10% more than people who don’t regularly exercise. Additionally, even modest amounts of exercise were found to boost earnings.

The big questions: Does exercise cause greater earnings? Do greater earnings cause more exercise? Or are the two just correlated without a causal relationship?

Does Exercise Cause Greater Earnings?

Regular exercise could cause greater earnings over time due to exercise’s well-known effects on well-being including lower weight, better appearance, better heart health and greater mental function. All these benefits are plausible reasons why exercising could lead to greater earnings. Being heavier has a negative impact on earnings (see this IFOD on weight and income) and exercise and weight are correlated.

Do Greater Earnings Cause More Exercise?

Another possibility is that increased wages positively affect exercise. Those who make more may have a greater ability to manage their schedules and fit exercise into their days.

Are Exercise and Earnings Correlated Without Causation?

It is possible that there is no causal effect. One possible non-causal relationship might be that the type of person who has the drive, discipline and dedication to exercise regularly may also be the sort of person who is a better employee.

So, What is the Answer?

According to Dr. Kosteas, the answer is that there is a causal link between regularly exercising and higher wages. He used a statistical technique known as “propensity score matching” to try to tease out causation from correlation. In short, he looked whether people fit the general profile of someone who was prone to exercise based on characteristics “such as age, education, and participation in high school sports. By comparing subjects with similar scores – only some of whom exercise – Dr. Kosteas was able to conclude that there is a connection between exercise habits and higher earnings.” Source. Additionally, the data showed that sedentary people who started to exercise saw a bump in their earnings.

Buttressing Dr. Kosteas’s conclusion is a more recent study of exercise and earnings in the Brazilian labor market which similarly found a causal link between exercise and earnings. That study noted, “physically active employees displayed better social and economic indicators compared to sedentary personnel. The results show that physical health status, reflected by the lower incidence of chronic disease and fewer doctor’s appointments, as well as higher average schooling are observed in workers who participate in physical activities.”