My son is a HS Senior running XC. He has never run well in hot weather. In his last meet, he said that his breathing was shot after a half mile. He struggled and lost to at least ten kids that he has beaten in previous races. He used an inhaler in his freshman year, then didn't seem to need it when he built a good aerobic base. Weather under 70 degrees for the 5K doesn't seem to be a problem at all, as he finished second and third in meets on tough courses. He has been diagnosed with allergies and has a prescription for generic Singulair.
So I am looking for advice. Hydrate - check. A stronger, more intentional warm up? He does warm up, but I think it needs some work. I was thinking of a warm up that includes bouts of race pace running, with use of an inhaler after it.
Any advice would be appreciated.