The one thing I harp on when it comes to building muscle is to get the adequate amount of protein in your system. If you do not, you will not build up healthy muscle tissue and wonder why you can not move faster and run harder. Here is some excellent information from Runner's World back in 2008 that can explain more!
Go to any prerace party or postrun potluck and you'll see legions of runners twirling forks in huge plates of spaghetti. And why not? Carbs are king, right? Except you may be missing out on another essential running nutrient, especially if you've been following the government's dietary guidelines. In September, the International Society of Sports Nutrition (ISSN) released a position paper by nine researchers in the field of protein and exercise. Their message? People who engage in regular exercise, like runners, don't just need more calories than desk jockeys, they need more protein.
What's more, high-protein intake has been shown to help maintain a strong immune system. "After an intense bout of exercise, your immune system is weakened for about four to five hours," says Richard Kreider, Ph.D., one of the ISSN study's authors and head of the Exercise and Nutrition Laboratory at Baylor University. "Protein stimulates white blood cells, which helps shield against upper-respiratory problems." Military research studies show that Marines who ingested high amounts of protein had fewer medical visits than those with lower protein intake.
The USDA's Recommended Dietary Allowance (RDA) for protein is .8 grams per kilogram (or .36 grams per pound) of body weight. But that's not enough for athletes, according to the ISSN, which says endurance athletes like runners need 1.0 to 1.6 grams per kilogram a day (or .45 to .72 grams per pound). That translates into 75 to 120 grams of protein daily for a 165-pound runner.
Lean meats and other animal products, like eggs, milk, and whey (a by-product of milk), pack a lot of protein. Four ounces of chicken breast, for example, contain about 32 grams of protein. The fat in food interferes with the rate of protein absorption, so limit your intake of high-fat foods, such as rib eye or prime rib. Vegetable-based sources, such as beans, lentils, nuts, seeds, and soy, aren't as protein-dense--a half cup of black beans, for example, has about eight grams--and they fall short on all nine essential amino acids, the chemical building blocks of protein (the exception is soy). Runners who avoid animal products can make up for this deficit by eating a variety of the most protein-rich vegetables and grains, such as soybeans, oats, and quinoa. "Not all the protein in a food is easily absorbed by your body," says Kalman. "But you'll probably get enough as long as you eat a lot of different kinds of food."So before you get in line for another serving of spaghetti, take a hard look at your plate. Chances are you should add some grilled chicken.