College students who want to boost their grades can start by boosting their level of exercise, new research suggests.

A report presented on Thursday at the American College of Sports Medicine’s 57th annual meeting in Baltimore finds that college students who regularly engage in vigorous exercise get better grades. Although a link between physical activity and higher academic achievement has been shown in middle-school students, it hasn’t been clear whether exercise is associated with better grades among older students.

To find out, researchers at Saginaw Valley State University in Michigan tracked the grades and exercise habits of 266 undergraduates. They found that students who regularly participated in vigorous physical activity had higher G.P.A.’s.

But does exercise really boost grades — or are high academic achievers simply more likely to be higher achievers in physical activity as well?

To answer the question, the researchers controlled for a number of factors that might influence grade point average, like gender, study time and participation in college sports. They even controlled for area of study, noting that a kinesiology major, for instance, might be more likely to exercise than a student studying another subject.

After controlling for such variables, the findings still showed that exercise made a sizable difference in a student’s G.P.A. On a 4.0 grade scale, students who exercised vigorously seven days a week had G.P.A.’s that were, on average, 0.4 points higher than those who didn’t exercise. (The full study isn’t available online, but the American College of Sports Medicine has posted a press release about the research.)

Although the researchers controlled for the amount of time a student spends studying, earlier reports showed that students who study a lot are also more likely to exercise regularly, suggesting a high academic work ethic may also translate into a higher commitment to exercising.

Notably, a study published last year in the journal Medicine and Science in Sports and Exercise found that the more hours a student spends studying, the more likely he or she is to exercise. Compared with students who studied less than an hour per day, students who studied three or more hours a day were nearly four times more likely to participate in vigorous exercise and about three times more likely to take part in moderate physical activity. And students with G.P.A.’s of 3.5 or higher were three times more likely to participate in vigorous physical activity than students with a G.P.A. under 3.0.

Correction: An earlier version of this post misstated the name of the university where the research was conducted; it is Saginaw Valley State University in Michigan, not Saginaw State University.