The Ab workout !

Since last November I have been trying to get a perfect six pack and im supposed to do that by the end of April. I've been working hard for the past months and it is paying off but I can only see muscle building in the upper-abs but i didnt really see a change in my lower-abs. So I asked my instructor for help. And he told me to carry around heavy things, but not too heavy so i wont hurt my back. So I was releived because thats doesnt seem hard to do, everytime they need help moving something around at home I would run to help them, and I'm always the first one to carry the new TV or microwave from the car, but then after a week of that I realised that this is not going to work so I started to slack off on that. But then after a while I started to see a really big change in my lower ab section and I think its from carrying around heavy thing. So its an easy way to build up lower abs.