He seems to be enjoying what he's doing
The expression on his face when lifting weights is like a kid in a candy-store.
That's the most important thing, to do what you enjoy the most, that's how you will excell and be good at something.
When it's not an effort or forced, but you instead enjoy it, that's what gives the best results.
The only problem is if he would get an injury preventing him from lifting, what would happen with his mental state then?
Would it be like a Painter would feel knowing he would never be able to paint again?