I had my sons 3 years ago. Im big into yoga and functional fitness (cross fit) my body is very fit and toned, I lost all the baby weight and then some. However no matter how much I work out my tummy is not flat or firm. Its frustrating because I’m in the best physically shape and health in my life but I cant make my tummy firm up. I’m wondering if its because I got so many stretch marks while being prego and if my skin will never go back. Or is there something besides diet and exercises I can do since I already have those angles covered. Thanks