Just How Much?
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. Don't worry about "overdosing" on protein. While some reports claim that high-protein intake is linked with kidney problems and calcium loss, the ISSN says it's not a concern for healthy athletes.
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 8 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.
For an example of protein intake for one day:
A 165-pound runner needs between 75 and 120 grams of protein daily. Spread intake throughout the day, eating some at each meal, to ensure your body has a steady supply.7 a.m.
3/4 cup oatmeal + two scrambled eggs + 6 oz. orange juice + cup of coffee with skim milk = 25 grams
Banana + 2 tablespoons peanut butter = 8 grams
11 a.m. (pre-run)
Half a bottle of protein sports drink (about 4 grams of protein per serving)
12 p.m. (post-run)
Second half of the sports drink = 8 grams
Two slices whole-wheat bread, 4 oz. sliced turkey, 1 oz. sliced reduced-fat cheese, lettuce, tomato, mustard + 6 oz. fat-free yogurt = 40 grams
Mixed-greens salad with peppers, cucumber, and tomato; 1 tablespoon balsamic vinaigrette dressing + 4 oz. grilled salmon + 1 1/2 cups steamed broccoli and cauliflower + one medium baked sweet potato = 33 grams
Protein Total=114 grams
Stay healthy with our nutrition guide.