My ultimate fitness goal is to have a six-pack and to be RELATIVELY built. I know relatively built is a very vague phrase but it's the best way i could put it. I'm still losing weight, and want to take advantage of the mass I have right now as I understand that a skinny little pencil has a harder time gaining muscle than someone with some pudge. Right now I do a Pilates workout every-other day, and do upper body bench weight-lifting days in-between, and walk/run AT LEAST a mile those 6 days and completly rest on Sundays. My question is should i make those 3 days of weight lifting more muscle-group specific? Like chest, shoulders, back or something to that extent? Any iformation would be very valuable to me, thank you.