The Atkins Diet and the South Beach High Protein
diets continue to gather followers with the promise of holding the key
to easy weight loss. But if you are an athlete, you might want to question
this latest diet craze. Especially when you consider that much of the
weight lost on these diets is a direct result of fewer total calories,
and the water loss that occurs with muscle glycogen depletion. If you
are an athlete, you may realize that glycogen depletion is one of the
reasons athletes 'bonk' or 'hit the wall' in endurance competition.
Glycogen is the stored energy in muscle, and it helps muscles retain water.
This combination is critical for high intensity athletic performance.
Depleting these energy stores is hardly something that will improve athletic
performance. For a more details about the nutrient needs and the best
fuel for endurence exercise, read Eating
for Exercise.
While endurance athletes are easy to convince of the need for a high carbohydrate, low fat diet, strength athletes tend to believe that they require more protein. This is rarely the case. According to sports nutritionists strength athletes require high carbohydrate and adequate glycogen stored in the muscle. They point out that all high intensity, powerful muscle contractions (such as weight lifting) are fueled with carbohydrate. Neither fat nor protein can be oxidized rapidly enough to meet the demands of high-intensity exercise. Adequate dietary carbohydrate must be consumed on a daily basis to restore glycogen levels.
In fact, research shows that high protein/high fat diets can hurt performance. An inadequate amount of carbohydrate in the diet can result in:
• Reduced muscle gycogen stores in the muscle and liver
• Decreased endurance
• Decreased maximal effort
• Decreased serum glucose levels
• Increased risk of hypoglycemia
High protein/high fat diets can also have a negative overall impact on health, including the following:
• Increased risk of certain cancers
• Increased calcium excretion and increased risk of osteoporosis
• Reduced intake of vitamins, minerals, fiber and phytochemicals
Research hasn't shown this. In fact most strength athletes get far more protein than is necessary to promote muscle synthesis. The current protein recommendations for optimal muscle building in a strength athlete is 1.6 - 1.7 gm protein per kg of body weight. For a 200 lb athlete that is a total of 145 - 154 grams of protein a day - about 3 small chicken breasts. There is no scientific evidence that more than 2.0 grams of protein per kg of body weight has any additional benefit in muscle strength or size.
How Much Protein Is That?
Not much, as it turns out. Here is a list of high protein foods.
Food Amount Protein Fish 3 oz. 21 grams Chicken 3 oz. 21 grams Turkey 3 oz. 21 grams Meat 3 oz. 21 grams Milk 8 oz. 8 grams Tofu 3 oz. 15 grams Yogurt 8 oz. 8 grams Cheese 3 oz. 21 grams Peanut Butter 2 tbsp. 8 grams Eggs 2 large 13 grams
The recommendations of sports nutritionists continue to show performance enhancing benefits. These general guidelines are:
• 12-15% of daily calories from protein
• 25-30% of daily calories from fat
• 55-65% of daily calories from carbohydrate
• An athlete's nutrition plan should be individualized to meet the needs of training and competition
• Carbohydrates are the primary fuel for intense muscular efforts, and should be the cornerstone of an athlete's diet, regardless of the sport they play