My son just turned 13 and does a lot of swimming. He is 5'8 and 103 lbs. How to put on lean muscle without too much bulk? Or is this even a concern at 13 yo?
Edit: He will be at regionals this week. He gets beat by kids that are shorter but are more developed.
I will also offer my advice as I have some experience in this regard. When I was at UT, I was 6'2" and 170 lbs. I was a skinny little basketball player who could jump with the best of em. But muscular? Nope, not close.
About age 26 my knees started bothering me so I dropped basketball and pocked up the weights. Today at 55 I'm 235 lbs, 15% body fat and can hack squat and dead lift over 400 lbs and bench around 300 on a good day.
Now this is nothing compared to guys on the UT football team but for my naturally skinny little ass, it's nothing short of phenominal. So how did I make that transformation?
Well, a couple of things happened.
1st. I got older and my metabolism slowed down. This actually helped me to add and keep muscle. No help for your son here, sorry.
2nd. I radically changed how I ate. No more eating 2 or 3 meals a day. I kicked that up to 5 times a day with the 5th meal often coming at 3 am. Massive amounts of PROTEIN and GOOD FATS. Think of building your body like building a house. Proteins are the wood and metal while Fats are the nails, cement and screws. You have to have both to be successful. And consume clean carbs when possible. Look at glycemic indexes and total calories for that. You want those low.
3rd. I stopped doing aerobics. I noticed that I would put on good muscle when I would stop running on the treadmill and lose it when I started back up. Long duration exercises burn muscle . . . do intense, short duration sprints instead.
4th. Lift weights with perfect form and heavy. If you can do more than 12 reps, up the weight. Do basic, multiple muscle group movements. Bench, squat, deadlift, lat pulls.
5th. Go to sleep! I can't emphasize this one enough.
Nueces your son is very young so this both hurts and helps. His metabolism will take off muscle and fat as fast as he can put it on. You have to slow down the former and speed up the latter. Lift, eat, sleep, eat again.
And dont worry about him getting bulky, not gonna happen unless you start shoving Anadrol tabs down his throat.
Hope this helps.