Im a very active 15 year old n im trying to put on as much weight as possible… but i also want to continue getting stronger. Next week im gonna start going to a summer fitness program at my high school. Starting at 8:30 we do running exercises on the track and bleachers for an hour.. then we lift weights for another hour (we alternate upper body and lower body lifts everyday). I want to do more by doing upper body or lower body workouts (depending on wat i worked on in the morning) every afteernoon at 6pm for an hour. The program at school is just mondays- thursdays, other then doing my workouts in the afternoons mon.- thurs., i want to also workout out on sat. and sun. I know i have to rest but i dont know if resting on fridays is enough. Is this healthy? Will it benifit me or hinder muscle gain?… And also any tips for weight gaining with a fast metabolism? (Im currently taking mass xxx). Please get back at me. Thanks.