ter-o's not saying thats his abs (Thats clearly just the armour's shape). And no, his muscles wouldn't show through the armour but I suppose abra71 just wants his character to look strong, why not help him with his work instead of going around in circles guys?
I would advise you to work from actual chain mail references abra instead of working as if you were pixeling plate, if your character was so toned his figure would show to a degree but not as extreme as you've made out. It's ok to exagerate but working from whats true to real life is better practice, because as stated runescape game graphics are hardly the ideal thing to go by, even with the updates.