Livestrong have an interesting article that may be of help to you, according to them (I will attach Webpage at the end):
You can attend part-time or full-time and choose a major in physical education, exercise physiology or human kinetics.
Its a good place to start, but I would recommend having a scout around some university webpages, as well as talking to either your Careers advisor or even your Physical Education teacher, might give you some more grounding for your ideas .
A Friend of mine used to be a fitness instructor and then moved into personal training (hes now in the police however)
and he hasn't got any thing higher than A levels he just started from the ground up with a level 2 BTEC in health and fitness training .
Although obviously only applies to the U.K. so if your elsewhere the situation is probably very different.
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