I've been exercising my abdominal muscles recently. I think my abdominal muscles are very standard, and my abdomen feels bloated, but my deltoid muscles near my shoulders also feel sore. Why?
This is normal, because when you exert force on your abdominal muscles, your whole body is tense, and the muscles at the back of your neck will ache unconsciously. This is normal. Try to focus on your abdominal muscles, so that you can exercise your main abdominal muscles and get used to it after a long time. I am an abdominal ripper myself (there used to be a video), and this will happen to me. Don't worry, keep insisting!