High Protein Diets Don't Deliver


	CLIPBOARD \| HEALTH

HIGH PROTEIN DIETS DON'T DELIVER FOR ATHLETES

Bob Murray, PhD, FACSM

Chris Rosenbloom, PhD, RD

Many of today's athletes are confused about the role of carbohydrate versus protein in their diets. They incorrectly believe that carbohydrates are bad because they stimulate insulin which, in turn, might make them fat. They believe they should avoid carbohydrates and instead, consider protein as the most important nutrient in helping them build and maintain muscles.

Their beliefs are strengthened by articles and advertisements in popular health and fitness magazines touting "carb-free" energy drinks, "zero-carb" energy bars and "low carb" nutrition shakes.

This article will explore each of the above statements and reveal that, although confusion abounds about the value of carbohydrates in the diet, it is an essential nutrient for athletes.

Myth: Carbohydrates are bad

It is tempting to label nutrients as good or bad, but both carbohydrate and protein are critical to good health and exercise performance. The key is that they perform different roles and one cannot substitute for the other.

Carbohydrate is indispensable for training and competing and is the preferred fuel for working muscle. It -

Yields more energy for muscular work than protein or fat.
Provides energy more rapidly to working muscles than protein or fat.
Is the only fuel that can be used anaerobically or without oxygen.
Without carbohydrate, athletes would not be able to perform activities that require fast oxygen to the muscles. Think of a fast break in basketball, a field-length scoring drive in soccer, a 10-K run, a kickboxing class or a swim workout. Virtually every athletic pursuit depends upon an adequate supply of carbohydrate.

The fact is carbohydrates like whole grains (whole wheat, pumpernickel, cracked wheat breads, whole wheat pasta, brown rice, quinoa, oatmeal), vegetables and whole and dried fruits are good for the body. They provide it with:

Glucose needed to fuel muscles and store extra glucose in muscle in the form of glycogen.
Nutrients such as the vitamins thiamin, riboflavin, niacin and folate - the minerals iron, chromium, magnesium and phosphorus.
Phytonutrients (plant substances) like antioxidants that protect the body from damaging free radicals.

Myth: Carbohydrates make you fat

Carbohydrates do indeed stimulate insulin release from the pancreas, but insulin is a very important hormone. (Just ask anyone with diabetes).

To the contrary, insulin unlocks the key to cells so fuel can enter the muscles. As an anabolic hormone, it also helps facilitate the entry of amino acids into muscles so they can be built, maintained or repaired.

While insulin, which is stimulated by both carbohydrates and protein, does facilitate the storage of excess calories into fat cells, it does not promote weight gain. And, insulin will not convert carbohydrate into fat when the carbohydrate is needed for fuel or as an energy reserve in muscle.

Excess calories, whether from carbohydrate, protein or fat, cause weight gain.

Myth: Avoid foods with a high glycemic index

After exercise, muscles need to resynthesize glycogen. Unfortunately, recovering lost glycogen is often difficult for athletes who train every day. Consuming foods (i.e., most breads, breakfast cereals and potatoes) and fluids (i.e., sports drinks) with a high glycemic index can help these and other athletes recover faster and prepare them for their next workout.

Myth: Protein is the key to building muscle mass

Protein is the building block for making hormones, enzymes and blood cells. It also helps build and repair body tissues, including muscle, and maintaining a healthy immune system.

However, protein is not critical for fueling working muscles. When carbohydrate is in short supply, protein can be used as a fuel. But then it gets diverted from its more important roles. For that reason, carbohydrate intake should be adequate enough to do its job - provide athletes with the energy they need for the occasion.

Athletes do need more protein than their sedentary counterparts, but when carbohydrate intake is adequate, their protein needs are only modestly elevated. These needs are easily fulfilled through a diet containing foods like eggs, beef, chicken, turkey, fish, cheese, milk, yogurt, nuts, soy and protein-rich vegetables like lentils, baked beans, black beans and kidney beans.

Nutrition shakes or energy bars that provide both carbohydrate and protein are also a good source of energy. Protein paired with carbohydrate has been shown to help build muscle mass when taken before or after exercise.

Still, most researchers agree that a small meal or snack containing carbohydrate and protein consumed shortly after exercise is enough to give muscles the nutrients needed to stimulate hypertrophy.

This all goes to show that carbohydrates, consumed from the right sources and in the right amounts, provide athletes with the energy they need to perform at their best.