College is a balancing act, and it can be hard to manage the demands of classwork while staying healthy and fit. But spending an afternoon at the gym might yield positive results in the library, a new study finds. When college students exercise more, they don’t just get healthier -- they are also more likely to succeed academically. The study, conducted by researchers at North Carolina State University, looked at 20,000 students’ recreational activities during the 2013-14 school year. When students increased their weekly physical activities by one hour, they were nearly 50 percent more likely to graduate.