Sometimes training is doing nothing. Most serious runners realize that deliberate rest and recovery is as much a part of training as is running itself.
Something that might not be quite as well understood is that the same applies to eating. Right now, three days before the Hotfoot Hamster 12-hour race, the very best training I can do is not to add miles and hills and speed, but simply to abstain from eating. So as I sit here at my desk at work, enduring not eating instead of heading for the break room and scooping up some pretzels or chips or going to the cafeteria to buy something, I am doing the best training I can do at this moment.
Thinking about it makes it harder, so I'd better get back to work.