You've probably heard of D.O.M.S. - Delayed Onset Muscle Soreness. This is what you experience two days after lifting weights after several weeks off. You're sore and stiff for a couple of days, but it doesn't happen immediately after lifting.
I think there may be something along the same lines I'd call D.O.F. - Delayed Onset Fatigue. I see this in other athletes and myself a lot. The day after a very hard workout or race the athlete doesn't feel too bad and the training reflects that sensation. But the following day, two days after the killer workout, the fatigue is really a heavy burden. It's all the athlete can do to get through it. I've never seen this discussed before but I see it too often not to be real.
I'm curious. What's your experience? Ever have this happen to you?