I am 13 years old and I play rugby union.I am 5' tall 98 pounds. This year I am trying to get number 7 (flanker). I want to pack on some muscle and gain some strength while maintaining my speed. At the moment I lift weights and do sprint training. My routine now is like this. Monday - Weightlifting - Legs. Tuesday - Sprint Training. Wednesday - Weightlifting - Chest/Shoulders/Triceps. Thursday - 4km Run. Friday - Weightlifting - Back, Biceps, Abs. Recently I have been cleaning up my diet for high carbs high protein low fat. Please give me all the advice possible! Cheers.