Went for a 50 mile ride today on our tandem (was supposed to be 64). Temperatures got over 100 degrees and 35 miles in we couldn't get our ride up a 4% grade without my getting really hot: some walking was involved.
Now we don't intend to repeat this experience, but I'm wondering physiologically, why heat has such a drastic effect on performance? I'm assuming this is the bodies self-protection mechanism to keep core temperature in line. Wound up taking a cab from th e 50 mile point back to the car and returning to pick up bike and stoker.
Background - returned to cycling last August after 20 years. both in our early 60's. Used to run decently fast marathons into my early 40's and didn't like the heat then either. This was a distance we've riddent 2-3 times and I'm confident we would have been fine with moderate temperatures. We did keep hydrated and I had electrolyte supplements (Nuun tablets plus gatorade/water)