Quite a while ago I have started an extreme diet over night and at same time I was exercising intensely regularly and because of lack of eating and nutrition over the course of 2months my skin started to get tight and tighter to the point where I couldn't look up because my neck muscle became tight I couldn't do regular movements like abdominal twist and range of motion throughout my entire body was limited because my skin became really tight and I have been trying to stretch my skin through exercise and heavy eating . The problem I've been having right now is that ,u see when you eat foods it stored in the muscle as energy and when you exercise the particular muscle energy depletes and the body gets energy from elsewhere so basically my stomach muscles has a lot of energy but not much any part of my body for example I can exercise my stomach for a long time but any part of my body I can only exercise the muscle for very short time then the muscle becomes stiff and I have to eat immediately after to relax the muscle and basically I need help stretching the abdominal muscles