God, I envy you Alex! That's so awesome and I love the glossy look! I don't know about muscles all too well, but this definitely helps. I thought I was finished, but I guess not. I really want mine to look like yours. I'm going to try to get the same effect without copying it. Where do you get that beige color from anyway? It seems so random in relation to the green, yet it works so well.
Also, is anything wrong with the legs?
EDIT*
I tried to make it similar without copying, just quickly editing it. I understand the back muscles more than I used to to be honest.
I don't want to go too much into realism because I'm thinking of making him a KoS sprite which seem a lot more simpler than this. Although, I'd love to keep working on him with these colors.