Protein Power

Finding the Right Balance in Your Diet

As much as you might like bagels and pasta, athletes involved in endurance activities can’t live on carbohydrates alone. Endurance exercise increases your need for protein. In fact, your daily protein requirement may register higher than that of strength and power athletes.

Endurance athletes need protein to shore up the loss of amino acids oxidized during exercise and to repair exercise-induced muscle damage, especially the trauma that occurs during eccentric muscle work such as downhill running. Protein typically supplies less than five percent of daily energy needs. During prolonged bouts of exercise when glycogen stores run low, however, protein is used as fuel and may contribute as much as 15 percent of the energy needed. Dieting or failing to eat enough calories to match those burned during exercise, which may happen during periods of hard training, also raises daily protein needs.

How Much Protein Do You Need?

Endurance athletes require 0.55 to 0.75 grams of protein per pound of body weight (1.2 to 1.7 grams of protein per kilogram). For example, a 120-pound athlete needs about 75 grams a day, while a 150-pound athlete should get about 95 grams. Competitive athletes involved in very intense training, such as ultrarunners, and growing teenage athletes may need as much as 0.8 to 0.9 grams of protein per pound.

This may sound like a lot, but most well-nourished athletes easily meet their protein needs. Consider this: eat two eggs and cereal with milk for breakfast, a tuna sandwich and yogurt for lunch, and grilled chicken with baked beans for dinner, and you’ve devoured almost 100 grams of protein. Between-meal snacks can also provide protein, and vegetables, whole grains, nuts, and tofu and other soy products supply varying amounts as well. Another bonus of including some protein at every meal (and snacks, too) is that it helps stabilize your blood-sugar level so you feel full longer.

Keep in mind that the goal is to maintain lean muscle tissue, not break it down during exercise for fuel. Beginning exercise with adequate glycogen stores and supplementing with carbohydrate (sports drinks, energy gels, and so forth) during prolonged exercise remains the best defense against delaying fatigue and preventing the breakdown of muscle tissue. Consuming protein shortly after exercise promotes the rebuilding of muscle proteins, and in some studies has been shown to help the body replenish its glycogen stores more quickly, at least over the short-term (the first four to six hours after exercise).

Despite the influx of protein-containing rehydration drinks on the market, however, the sports science community remains divided on the optimum amount and timing of protein following exercise. What does remain clear is that athletes who replace fluids and carbohydrates within the first 30 to 60 minutes recover more quickly than those who don’t. Adding some protein to this recovery mix isn’t likely to do harm, and protein-rich foods should definitely be part of your next meal, ideally eaten within an hour or two of exercise. However, unless you train twice a day or more, worrying about the exact carbohydrate-to-protein recovery ratio or makeup of your post-workout drink isn’t productive. The best strategy for ensuring glycogen resynthesis in time for tomorrow’s run hinges on you meeting your total energy and fluid needs throughout today.