I am a pretty healthy weight but I carry most of my fat in my stomach. I have been on a pretty strict diet and have been working out. In the last few days I have started to incorporate more abs exercises (lunges/crunches). I was pretty sore this morning, including my lower stomach. I noticed there's a pretty prominent indent below my belly button that almost makes both sides of fat around it look separate like a belly butt. I have tried to Google this issue (specifically related to weight loss and exercise) but come up with a lot of forums talking about a similar issue with pregnancy and muscles separating. I am not pregnant nor have I ever been. So, I am wondering: a) what on earth is this? b) does this soreness indicate that I somehow strained myself and separated the muscles? I read about people having this issue but it seemed either pregnancy related or something they have had all their lives.. not something that just suddenly appears. c) could this be related to ab/muscle formation? For those of you who have that definition-- did it start to come with the losing of weight in small chunks like that?