This is 1 question that has always been in my head ever since I started trying to go from fat and obese to muscular and healthy weight. If my abs are sore or down and outright in pain, I will not do abdominal exercises. I sometimes will do sit ups to relieve gas if having a bowel movement isn't helping. In rare cases that I have both intestinal and stomach gas, sometimes if I have a bowel movement and my torso is at a 45 degree angle from the pelvis the extra abdominal pressure pushes the gas out of both ends. But there is 1 thing that I have every month that makes me want to stop exercising my abs until it is gone. That is menstrual cramps. Ovulation pain I get late at night in combination with nausea and that is long after any abdominal exercises so ovulation doesn't stop me. But menstrual cramps can occur at any time of day and any reasonable time relative to the start of my period. This is why I don't exercise while I am on my period(or at least while I have the cramps). And here is my reasoning as to why I shouldn't exercise when I have menstrual cramps: The uterus is a muscle and like any muscle, it contracts. Prostaglandins make the uterus contract more forcefully and this causes the endometrium to get ischemic which ultimately leads to your period. These uterine contractions I can sometimes feel on top of the cramps and I know when I have a contraction when the pain gets worse for a few seconds. If I exercise my abs while my uterus is contracting, it could cause me to have more uterine pain which would make me stop the exercise because the external pressure the abdominal muscles put on the uterus will make it contract more during the exercise than before or after. Exercising my abs when I am not on my period can actually decrease the amount of pain I feel from the uterus to the point that in just a few months, my periods could be painless or at least not so painful that I can feel contractions. I guess you could say that it tones my uterus. So I don't think I should exercise my abs when I have menstrual cramps. But is this actually true, is my reasoning right?