Bad Cramps

Fiber may be contributory. Are you drinking the same amount/enough water, and bowel movements normal? (Sorry, TMI, but relevant). Lack of bowel movements is quite common if you cut down dramatically on calories, which will cause abdominal pain.

Cutting down on calories usually incurs hunger pangs/pains, but not necessarily the kind of pain you describe. I have to admit I don't know much about P90X or components, but if you are working out a lot, could you have sustained an injury?

I have had a abdomen injury before this is not one. They are cramps, they last for a few minutes then go away for a little while. I am drinking a lot of water easily 100 ounces a day. But now that I think about my bowel movements have not been as frequent as normal. So maybe constipation? Can that be a result of cutting back?

I'm not a healthcare professional, but from my experience of constipation (a lot of experience!) I frequently get abdominal cramps if I haven't been, or if I need to go urgently. When I have restricted on calories (probably less than 1300, but you've cut down dramatically so body won't recognise necessarily the calorific numbers but rather the effect) I have found that I don't go as regularly.

Certain foods make a difference, which is self explanatory, but the other thing I would mention is that if you take certain medication (I'm talking prescription or pharmacy) it can bind you - when I had a virus last week and had to pop paracetamol to keep a fever down, I didn't go well or regularly but I was also not eating as much.

Am I right in thinking that P90X promotes high protein/low carbs initially? If that is a big difference to how you were eating beforehand, that can take time to adjust.

Muscle cramps could be from your electrolytes being out of balance. Make sure you are getting enough potassium in your day. I have problems with low potassium so I use "Half Salt" (which is a product that contains 1/2 sodium chloride 1/2 potassium chloride) to cook with. If you can't find that you can always get "no salt" which is 100% KCl and mix it 1/2 and 1/2 with your regular salt.

If the pain is more Gastrointestinal it could also mean you are constipated - in which case fiber supplements and plenty of water is your best friend.

Dehydration!!! I'm no doctor, but it happened to me with Insanity. I was drinking a lot of water at the time, too! It just wasn't enough for all the activity I was doing.