4 Reasons Why Athletes Need More Dietary Protein

December 19, 2011

by Cathe Friedrich

How much protein do athletes need? According to RDA guidelines, sedentary people need about 0.8 grams of protein per kilogram of lean body mass each day. So, an inactive person who weighs 150 pounds (69 kilograms) would require around 54 grams of protein each day. There’s some controversy as to how much athletes require and whether they actually need more protein in their diet. Most fitness experts believe athletes should get between 1.2 grams of protein per kilogram of body weight and 1.8 grams per kilogram depending upon their level of activity. Have you ever wondered why athletes need more protein than a sedentary person? Here are four reasons why athletes have higher protein requirements than people who don’t work out.

Muscle Repair and Recovery

Exercise, especially strength training, causes microscopic damage to muscle fibers, which has to be repaired. When you increase the tension in a muscle by lifting a weight, it activates signaling proteins. These proteins turn on genes involved in protein synthesis. This is how muscles hypertrophy or grow larger. Even during endurance training, protein breakdown is greater than it is at rest, and dietary protein is needed for repair and recovery.

Protein Can Be Used as Fuel in Some Situations

Carbohydrates and fats are the main fuel sources for exercise, but athletes use protein for fuel in some cases. Normally, only about 5% of the fuel used during exercise comes from protein, but that amount needs to be replaced. Protein becomes an energy source during long periods of endurance exercise when blood sugar and glycogen levels are low. In this case, the liver can convert amino acids to glucose through a process called gluconeogenesis to supply the body with additional glucose. That’s why it’s important not to exercise for long periods of time in a carb-depleted state.

Athletes Can Lose Protein Through Urine and Sweat

Athletes also lose small amounts of protein through urine and sweat, which needs to be replaced. Protein losses are greater with higher intensity exercise and may be higher in athletes that don’t stay well-hydrated or take non-steroidal anti-inflammatory medications.

Athletes Have a Higher Lean Body Mass

Most athletes, with the possible exception of long-distance runners, gymnasts, and ballerinas have greater lean body mass than a sedentary person. This increases their protein requirements.
When an athlete doesn’t get enough protein, they can go into negative nitrogen balance and lose muscle mass. Fortunately, most athletes can supply their protein needs by eating lean protein sources such as turkey, chicken breast, fish, cottage cheese, eggs and vegetarian protein sources such as beans, lentils, tofu, and tempeh. Protein powders and supplements aren’t necessary.

The Bottom Line?

Athletes have higher protein requirements for the reasons listed above, but this can come from food rather than protein supplements. Most meat, poultry, and fish have 7 grams of protein per ounce and a single egg has 7 grams of muscle-building protein. Getting protein from food sources is also cheaper than buying overpriced protein supplements.

References:

The American Association for Clinical Chemistry. “Exercise-Induced Proteinura in Well-Trained Athletes”
Exercise Physiology. Fifth edition. McArdle, Katch, and Katch.