KSH - I'm assuming you've tried everything but... I was just reading that it may help to breathe IN when you step on your left foot and out on your right. Personally, I take two little breaths in and two breaths out once I'm working hard so do two in (starting on left foot, and two out, starting on left foot again). Does that make sense? Also that breathly in deeply is important to get the lungs fully inflated and push down the diaphragm. I don't get side cramps so it's not a problem for me but my son does and it seems to help him.