Ingesting carbohydrates after a workout is essential. If you're not, your body will be forced to utilize muscle as a source of fuel.
Ingesting high glycemic carbohydrates post workout will allow you to jump start glycogen synthesis, restoring the glycogen that's been drained from your workout. Along with that, the high blood-glucose level will allow for an insulin release, acting as a nutrient shuttler to your muscle cells.
Ingesting protein workout is just as important, or else you won't begin protein synthesis, and recovery will be a slow process.
That post workout shake or meal is essential to recovery and growth!!!!