Re: This is pretty strange. Sit-ups causing constipation!?
Yes, sit-ups can cause constipation.
This has happened to me before too. Although I have never really been constipated, I have found that the times when I have done sit-ups, it has been a lot harder to have a BM. I think that it is due to the fact that when you do sit-ups all the muscles in your belly become tighter and a little more tense. When you open your bowels, you need these muscles to relax so that you can have a BM. Due to the exercises it is harder to relax these muscles, so when you try to have a BM you probably have to push harder and you become a little constipated. This normally resolves when you leave the sit-ups for a bit and let your belly muscles relax.