Many athletes worldwide, including those in the CrossFit community have adopted the Paleo Diet because they have observed that it helps them to increase muscle mass, reduce body fat and train at greater intensities. These characteristics ultimately result in enhanced performance. In a nutshell, there are four basic reasons why the Paleo Diet enhances athletic performance or is ergogenic.
1.Branched-chain amino acids
First, the diet is high in animal protein, which is the richest source of the branched-chain amino acids–valine, leucine, and isoleucine. Branched-chain amino acids (BCAA) are different from other amino acids that collectively make up protein in that they are potent stimulants for building and repairing muscle. This information is relatively new and has been reported in the scientific literature in the past decade or so. But the caveat is this: These amino acids work best when consumed in the post exercise window.
Lean meats and fish are far and away the greatest source of BCAA. A 1,000-calorie serving of lean beef provides 33.7 grams of BCAA, whereas the same serving of whole grains supplies a paltry 6 grams. Because many endurance athletes focus on starches (breads, cereals, pasta, rice, and potatoes) and sugars at the expense of meats, particularly following a hard workout, they get precious little muscle-building BCAA in their diets. By consuming high amounts of animal protein (and hence BCAA) along with sufficient carbohydrate, athletes can rapidly reverse the natural breakdown of muscle that occurs following a workout and thereby reduce recovery time and train at a greater intensity at the next session. Athletes worldwide who have adopted the Paleo Diet typically report of improved recovery with these dietary recommendations.
2. Blood acidity versus alkalinity
In addition to stimulating muscle growth via BCAA, the Paleo Diet simultaneously prevents muscle protein breakdown because it produces a net metabolic alkalosis. All foods, upon digestion, report to the kidney as either acid or alkali (base). The typical American diet is net acid producing because of its high reliance upon acid-yielding grains, cheeses, and salty processed foods at the expense of base-producing fruits and veggies. The athlete’s body is even more prone to blood acidosis due to the by-products of exercise. One way the body neutralizes a net-acid-producing diet is by breaking down muscle tissue. Because the Paleo Diet is rich in fruits and veggies, it reverses the metabolic acidosis produced from the typical grain-and starch-laden diet that many athletes consume, thereby preventing muscle loss.
3. Trace nutrients
Fruits and vegetables are also rich sources of antioxidant vitamins, minerals, and phytochemicals and, together with fresh meats (excellent sources of zinc and B vitamins), promote optimal immune-system functioning. The refined grains, oils, sugars, and processed foods that represent the typical staples for most athletes are nearly devoid of these trace nutrients. From examining the training logs of numerous people he has coached, my colleague and co-author, Joe Friel (an internationally known triathlete coach), has found that the frequency and duration of colds, flu, and upper respiratory illnesses are reduced when athletes adopt the Paleo Diet. A healthy athlete, free of colds and illness, can train more consistently and intensely and thereby improve performance.
4. Glycogen stores
One of the most important goals of any athletic diet is to maintain high muscle stores of glycogen, a body fuel absolutely essential for high-level performance. Dietary starches and sugars are the body’s number one source for making muscle glycogen. Protein won’t do, and neither will fat. Athletes and sports scientists have known this truth for decades. Regrettably, they took this concept to extremes; high-starch, cereal-based, carbohydrate-rich diets were followed with near-fanatical zeal 24 hours a day, 7 days a week.
It is a little known fact, but, similar to the situation with branched-chain amino acids, glycogen synthesis by muscles occurs most effectively in the immediate post-exercise window. Muscles can build all the glycogen they need when they get starch and sugar in the narrow time frame following exercise. Eating carbs all day long is overkill and actually serves to displace the muscle-building animal proteins and alkalinity-enhancing, nutrient-dense fruits and veggies that are needed to promote muscle growth and boost the immune system. Many Paleo friendly fruits and veggies are effective in restoring muscle glycogen, particularly net-alkaline-producing starches found in bananas, sweet potatoes, and yams.
Loren Cordain, Ph.D., Professor Emeritus
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