Nutrition following a training session is one of the most important recovery factors that you can control. You've just spent the last one, two, or five hours depleting your energy stores and pounding your muscles. Not only is it important to replenish these stores so you can recover quickly and exercise again soon, but consuming enough energy is also critical for gaining fitness as well as maintaining and building lean muscle. The exercise provides the stimulus needed for adaptation, but the body will only grow stronger if you supply it with enough energy.
Your body is most efficient at replenishing its energy stores during the first 15 to 60 minutes immediately following exercise, so it's important to consume enough food and the right foods to make the most of this time.
The best foods to do this are rich in carbohydrates, contain a small amount of protein, and are easy to digest (high on the glycemic index). A good rule of thumb is to take in 0.75 grams of carbohydrate per pound of bodyweight within the first 15 to 30 minutes. This could be a snack, a carbohydrate-rich recovery drink, or a bargel. Immediately after exercise, your body doesn't really care if it gets simple or complex carbohydrate, as long as it gets the carbohydrate. Studies show that simple sugar and complex carbohydrate are equally effective for replenishing muscle carbohydrate stores.
Soon after, a complete meal that is rich in carbohydrate and moderate in protein and fat is best for recovery. For instance, a meal with brown rice, chicken breast, and roasted or steamed vegetables would do the trick. Having a turkey sandwich on whole grain bread or in a whole wheat tortilla, with plenty of vegetables stacked in it, would also work and you may be able to have it waiting in your vehicle if your workout starts and ends at a trailhead.