I'm having an issue with very painful side stitches. I've done a search already and read the threads, but mine is happening during the same, very specific conditions - (i) after an extended stay in aero position on my tri bike and (ii) in temps over 90 degrees. Typically occurs within minutes of starting the run. Only happened to me a few times, but it's torpedoed three different races (two 70.3 and one IM) where I had to walk extensively on the run as a result. Never had it happen in more modest temperatures for races or long training days. I've only recreated it in training twice (today included), and both times I rode 100+ miles on my tri bike and ran afterward when temps where in the 90s. I think my hydration is good but maybe not. For nutrition I've relied on double servings of Infinit per bottle (roughly 200 calories per hour) and Cliff Shot Blocks once an hour, so roughly 300 calories an hour.

Anyone have this specific issue? Any thoughts on a cause? I'm training for IM Choo and feeling real good about my fitness. However, if it's an especially warm day come race time and I don't change something, I'm certain all the fitness will be for nothing when I'm walking the run course because of a recurrence of this problem. If it helps any, I'm a slightly bigger athlete - 6'1", 185 lbs, so I know I'm at a disadvantage in the heat anyway.