A good friend on mine has an bachelors degree in Exercise Science. Now she's the general manager of a health and fitness club. I ask her advice about nutrition and different training methods all the time, she has a lot of great information. I remember shortly before she graduated she interned at a gym where some of the Atlanta Falcons and Atlanta Hawks train in their off seasons. I did a quick google search for "Exercise Science" and found a collection of links that look good although I haven't explored them:
http://www.uni.edu/hpl/links.html
If you are genuinely interested in this field you should do some research on which universities and colleges offer undergraduate programs. Then you can see what you have to do as a high school student in order to get into the school you want to go to. Whether or not you ever realize your goal of boxing professionally this would def. allow you to have a rewarding career long after you are too old to compete personally.