Ok, I usually grab something to eat about 30 minutes before I workout. Usually some high carb food. I find I can usually lift longer, feel better, etc... Then as soon as I'm done I'll slam down a shake.
Well I was pressed for time the other night and I figured I'd down a quick shake with some oatmeal blended in and just do a few crunches, some stairmaster, and then a heavy bag workout. 30 minutes on the Stairmaster, great feel awesome! Grab a plate and start doing some weighted crunches, after 3x100 a little sick to my stomach, but still feel pretty good. Last, I set my timer for 3 minutes and start with some light fast punches... ding ... Man, after the day I had at work that was feeling pretty good. Take a breather, set the timer for 3 more minutes... ramp it up with a jab/hook/body combo, really pouring some steam on now... ding... not feeling too bad, breathing heavy and drenched, but feeling good. Set the timer for 3 more minutes. I'm a right hander who fights southpaw, so I'm leading with my right with some moderately strong jabs, so this time I'm doing jab/jab/full power straight punch.. At about two minutes my left side goes to hell. Diaphragm starts to spasm. I double over and hit the floor. I then drag myself over to the waste bucket and return most of my shake back to the outside world.
Lesson learned. There is a reason boxers don't eat for 3 hours before a match... this would be part of it
Good times.