I just got in an hour ago from one of the worst rides of my life. Was supposed to be going from bristol to cheddar gorge, but i took a detour through weston super-mare on the way. It was cold and windy, especially on top of the mendips, pedalling into a strong headwind was pretty grim. I took my usual mix of one plain water bottle and one half orange juice and half water, and also took a camelbak with me so hydration definitely wasn't an issue. It was after i climbed up cheddar gorge, unusually slowly compared to normal, that i could feel my legs weakening. Within another 15k i had literally ground to a halt, legs were absolutely dead, they started to cramp, and no part of me wanted to continue. Thing is, I did this ride a few weeks ago and was fine. I had plenty of food, a large bowl of porridge 2 hours before i started, then my normal mixture of two bananas and some malt loaf stuffed inside my camelbak bag (not in the actual water part!). Had to stop at a shop and buy some lucozade and a couple of mars bars just to summon the energy to make it home, though it was dark by the time I did. The total ride distance was about 115km (so about 70miles i guess) Can anyone explain to me why this happened this time and not before?? I dont understand how i was fine last time and then this happened, even though I took the same with me and have had a very similar, and healthy, diet for the last few weeks, and my levels of fitness have not declined.