Hydration is important.
I relearned this lesson last night when I didn't go through my usual routine of drinking about 30 oz. of water in the 2 hours before class. I bought a sports drink on the way and did not realize until it was too late that it was frozen solid. So the whole way in, I was trying to suck and melt the hand-sized block of ice.
I tried to make up for it when I got to the dojo by drinking a glass of water, but I only made it about 30 minutes before I started to feel very queezy. I had no choice but to bow out. I couldn't believe it as I wasn't even working hard, but what can you do?
Before then, I was having a pretty good time in Luis' class with katatori menuchi, which is a pretty cool attack. Uke grabs the shoulder, then nage goes to strike uke in the face. Uke's "block" of that strike provides the attack that nage then deals with. Often, uke doesn't understand that his second action is supposed to be a response to something that nage does and attacks the shoulder and head at the same time. This is not the right idea.
Until I crapped out, I felt pretty good at leading uke. The best I've done with that attack so far, I think. :) I could actually feel myself blending with the forward motion to a much greater degree than ever before with this one. So I was happy. Hopefully, the next chance I get I'll have enough water first.