Go healthy, for yourself. If there’s a part of your body you have consistently wished were different and can be changed with exercise, do that. If there’s an exercise that you enjoy and makes you feel powerful, do that right after you do the one you hate but you know you need. Use the fact that the gym has all the equipment you can’t afford and the trainer to help you use them safely to get a really varied all-over workout, building strong bones and muscles and posture and blood flow. Boys and girls come in many sizes and shapes, so you can do either with clothing and style, and be fit because you’re fit. Edit: And don’t forget stretching for flexibility, in case of sex.