During post-exercise recovery, rebuilding with protein is necessary. Runners and other endurance athletes also need more protein because on long workouts their muscles burn some protein. These athletes need 1.2 to 1.4 grams of protein per kilogram of body weight per day. Because endurance athletes weigh less than strength trainers, the amount of protein needed per day is less. The protein goal is about 12 to 20 percent of total calorie intake.
Protein is required on a daily basis, but too much can be a problem.
Extra calories, no matter what the source, can be converted to stored body fat. And protein beyond these recommendations must be processed by the kidney and liver to rid the body of unwanted nitrogen byproducts. The kidneys have to flush out toxins in urine, so athletes getting an excess of protein could risk dehydration. Also, studies show that excessive protein may cause the loss of calcium in urine, which puts women at risk for osteoporosis. An ounce of meat, fish, chicken, egg or cheese contains roughly 7 grams of protein.