What you do after training is just as important as what you do during.
Its easy to do your training, finish and go about your daily business like nothing happened and be just fine. But if you want to really get the most out of your workout and become a better (stronger/faster/fitter/leaner/energized) athlete, well then you don't just stop... you complete your workout and then you RECOVER.
Recovering from your workout is equally important as fueling during a workout, hitting your paces, and completing set mileage. During the workout, your muscles have taken a beating. They are tired, torn and worn out. They need to be cared for, replenished and revived. Depending on the workout, this can take 24-48 hours to happen. In order to get stronger, your muscles need to rebuild and this starts with post workout recovery.
Want to know how I recover? Here's a recipe I use...