Yesterday we decided to forgo our usual group ride and shoot for 65mi @ 18mph. My normal Sunday ride is 50mi at about 19mph and we have done this 65mi course a few times this year. It was about 80F/85% RH and as usual I took 48oz of gatoraide and 2 power gels.
The ride is going along well until about 25mi when I start to feel a little tired in the legs and I am sweating even more heavily than usual(I sweat a lot). I start hydrating at a faster rate and get mid way through my second bottle by 32 miles plus have a gel. Now we start heading back and I am really feeling bad, no gas in the engine, can't go faster than 16mph. We stop at a grocery store and I buy another bottle of gatoraide and chug a coke. Feeling a bit better we start out, but now after about 10mi farther my thighs start cramping. I try to ride through it but just can't and end up calling my son for a pickup after 48 miles.
When I get out of the car at home both my legs go into complete cramping and I can't walk and I am gritting my teeth in pain. My hands and fingers also start cramping badly and I can't hold anything. After a bit of walking around the house in the AC and drinking more fluid things get better, but I am sore and tired today. I have no idea what caused this, I have ridden farther and faster in hotter weather before with the same level of hydration with no problems. Yesterday was hell and I hope it doesn't happen again.