The Downside to a Good Workout
An exhausting trail run can leave your body dehydrated, depleted of glycogen (carbohydrate) stores, overexposed to free radicals (leading to cellular damage) and cytokines (leading to inflammation) and suffering from tissue damage (mostly leg muscles and lungs). This "depletion" is what causes sore muscles, stiff tendons, creaky joints and low energy levels for a day or two following a hard effort. Studies from the Australian Institute of Sport and from Appalachian State University show that after a middle-distance race (five to 13 miles) as much as 70 percent of participants experience an upper-respiratory tract infection such as a cold, flu or sore throat due to a temporary exercise-induced suppression of the immune system.

An ideal recovery strategy involves immediately replacing what your body lost during exercise through proper recovery nutrition.

Nutritional Recovery Triad
Three aspects to optimal post-exercise recovery are hydration, glycogen replacement and "biochemical balance," which involves reducing inflammation in joints and muscles, reversing oxidation, repairing tissue and restoring the immune system. Oxidation and inflammation are related chemical reactions that cause cellular damage, leading to problems such as fatigue, infections and muscle soreness.

Since it can be difficult to drink enough during long, intense sessions, assume your body is dehydrated post-run and drink more than your thirst demands. Electrolyte beverages with a low sugar concentration are superior to water in the body’s ability to absorb and retain the fluid.

Despite the wide variety of bars, gels and beverages, the bottom line is to select something that tastes good and your stomach can tolerate. A post-exercise snack immediately replaces the sugar stores burned off during exercise. Consuming carbohydrates and protein in liquid form (such as one-percent chocolate milk) is a convenient way to refuel and rehydrate simultaneously. As a rule of thumb, consume around 300 to 500 carbohydrate calories as soon as possible following exercise. Great snacks are banana with yogurt, a handful of nuts and an apple or a bowl of whole-grain cereal topped with berries and one-percent milk. Wash down solid food with plenty of water or sports drink.

While rehydration and glycogen replacement replaces what your body lost, biochemical balancing restores the body’s chemistry to normal levels. Exercise-induced inflammation and oxidation damages muscles, lung tissue and temporarily suppresses the immune system. Until you have rested, you are at increased risk of colds, flu and other respiratory tract infections, injuries such as tendonitis, strains, stress fractures and overtraining which characterized by lethargy, depression and general moodiness.

Anti-oxidant-rich berries (blueberries, blackberries and raspberries), most fruit juices (orange, grape, and apple) and dietary supplements containing flavonoids and inflammation-reducing enzymes help repair tissues. Foods containing these nutrients are pineapple and papaya, roasted soy nuts and other soy products containing immune-balancing beta-sitosterol.

Powerful Protein
Although regular moderate exercise is associated with strengthening the immune system, intense training and competition suppresses immune function. The longer the event, the longer this affect can last. A marathon-distance run can leave an athlete susceptible to infection and viruses for up to two weeks, during which time the body cannot effectively fight off infections or repair exhausted muscles and joints.

Protein is made up of amino acids and is essential for rebuilding damaged muscle tissue and restoring immune system function. Protein-packed foods, such as milk or yogurt (non low-fat varieties) or a palm-sized portion of beef, poultry, fish or legumes (beans), provide amino-acid building blocks for tissue repair.

The immune system uses proteins made up of glutamine and the three branched chain amino acids (BCAA) as fuel. Whey protein, found in some post-exercise recovery drinks and dairy products, is a decent source of all four essential amino acids, but some studies suggest that amino acid uptake is faster when consumed as isolated nutrients in the form of dietary supplements. Look for products that deliver effective levels of BCAAs (1500mg) and glutamine (1000mg) in the proper ratios for post-exercise immune system support. Don’t fall for the "more is better" gimmick, but instead look for products that back up their formulations with research studies on runners.

All protein-containing foods will have some BCAAs and glutamine, but dairy products (because of their whey component) are a particularly good food source.

Recovery-enhancing nutrition may be the most reliable method to improve your trail running. Don’t just eat something after coming off the trail; instead, give some thought to "functional eating."

When to Eat What
Immediate after-workout snack
Within two hours of your run, consume an easy-to-digest carbohydrate- and protein-containing snack with plenty of fluid. A peanut butter and jelly sandwich is a great choice, but eat to satisfy your personal tastes. Immediate post-exercise snacks jumpstart your body’s repair process.

Evening Post-Workout Meal
Your post-run dinner is a major source of tissue-repairing nutrients. This meal should include adequate protein (such as a palm-sized portion of chicken breast), carbohydrates (one or two fist-sized portions, such as pasta), antioxidants (two handfuls of brightly colored fruits or vegetables, such berries or citrus) and some added fat (a golf ball or shot-glass sized portion of full-fat salad dressing or olive oil or butter).

Over the Next Week Before the Next Big Outing
Continue taking your amino acid supplements–BCAAs and glutamine–to ensure adequate immune system function and repair any lingering muscle or lung damage. Dehydration can persist for several days following a long run and even modest levels of dehydration can inhibit recovery, so be sure to hydrate adequately (indicated by clear urine) before your next trail run.

Shawn Talbott holds a PhD in nutritional biochemistry and MS in Exercise Science, and practices recovery principles after his trail runs in Utah’s Wasatch Mountains. He can be reached at smtalbott@supplementwatch.com.