I'm impressed you're thinking about this. I recommend making this an important factor in your decision. DO not select a work study if you have to constantly focus. Try to get one that allows you to work on homework in the downtime...even if it pays less :)
Freshman year can be tough. I suggest focusing on your grades and extracurricular activities during your Freshman and Sophomore years. It's important to establish a strong GPA during the first 2 years of college, so that your internship/job search later on becomes easier. Most companies start accepting interns during or after Sophomore year, so I recommend focusing on your school work and sports during the first year. If you have time to work, you can definitely apply for a part-time job on campus. For example, I worked part-time at one of the university coffee shops during my Freshman year just so I have some income while in school, but the majority of my time and effort was spent on my coursework. Also, if becoming an athlete is your passion, definitely put in the work to becoming great at that. Pro sports tend to recruit strong college athletes.
I thinks this is a tough question. In my personal opinion, you will need a lot of determination and organization to do both, but it is definitely achievable. What I did, was organize my school schedule to only have classes in the morning so I could work in the afternoon. I did have strict schedules with my self but that let me achieve my goals, and still have time for friends, family and myself!
Hope this is useful and you are able to accomplish it, good luck!