Just googled and seen this
"Eat within an hour after exercise.
During the first hour after exercising, your body is most able to absorb nutrients and repair muscles by restoring your glycogen reserves. This is because insulin that assists in protein re-building and enzymes that aid in metabolization are at the highest levels in the hour-window after working out.
It is also important to drink enough water within the first hour after exercise in order to help with muscle fatigue and lactate build up. Lactate is created when the body has limited oxygen. It breaks down glucose for energy. When there is extra lactate, water will help neutralize it because it is slightly alkaline. This will also keep you from overeating at the next meal."