My 12 yo son has been swimming for the past 7 months, he is swimming with the beginner group. He pretty much has all 4 strokes down, but is slow and doesn't have the endurance (they beginners only swim 25 meters at a time) one of the coaches and myself believe that he should move up to the next group so he can start building endurance. Unfortunately that coach doesn't make those decisions. The other two that do, one said he is gangly and skinny (but didn't come out and say that's why he isn't moving up) and the other flat out told me he's to weak. He is built like a baby giraffe. He's 5'3" and almost 77lbs. I've taken to making him protein shakes with ice cream and he's been doing this for about a week (before they said anything to me) and he hasn't gained even a half a pound. The kid eats like there is no tomorrow. What is high in calorie and good fats, and what kind of exercises should I have him do to add strength. I'm seriously at a loss! He wants to be competitive and he's willing to work for it.