A: There is a highly specialized and lengthy process used to manufacture Ig. It begins in blood centers across the country where tens of thousands of healthy individuals donate their plasma (the portion of the blood where the immune globulins and other blood proteins are contained).
Runners, especially those training for long distances such as marathons, should consume .5 to .75 grams of protein per pound of body weight. Good sources of protein are fish, lean meat, poultry, beans, nuts, whole grains, egg whites, low-fat milk, low-fat cheese and some vegetables.
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.