Both workouts were in the evening, right after work. I'd consumed about 1.5-2 liters of water up to that point in the day (which is about typical for me).
Creatine consumption was 5 g and caffeine was 200 mg.
Electrolytes could have been depleted I suppose, but, again, I wasn't doing anything different than normal, other than the caffeine.
I mean, it has to be either the electrolytes or the water. I was just surprised that this amount of caffeine could make such a difference.
Thanks for the thoughts so far...