ARTICLE 1: SOME THOUGHTS ON THE 40-30-30 DIET

Most endurance athletes have probably heard of the 40-30-30 diet and maybe even Read Barry Sears's book The Zone. The concept of maintaining a dietary macronutrient proportion of 40% carbohydrates, 30% fat and 30% protein was popularized by Dr. Sears; however the same concept is presented in Phil Maffetone's book In Fitness and Health, which predates The Zone.

It appears that the debate between the 40-30-30 dietary proponents and the high carbohydrate/low fat proponents is not going to be settled any time soon, so I thought I would throw my comments into the fray. First of all, the need for endurance athletes to consume an adequate amount of carbohydrates to maintain glycogen levels has repeatedly been demonstrated in numerous scientific studies. Dr. Michael Colgan (having met Dr. Colgan personally I can attest first hand that he is one of the most brilliant minds in Sports Nutrition today), author of Optimum Sports Nutrition, estimates that an athlete needs from 3.5 to 7 grams of carbohydrates per pound of body weight per day, depending on the number of hours of daily training.

These numbers are derived from Dr. Colgan's review of scientific literature and from his practical experience with many elite athletes. For a 150-pound athlete training 2 hours a day this amounts to 525 grams of carbos per day. If this person followed the calculations in Dr. Sears's book to determine the amount of carbos on the 40-30-30 diet, he would only be taking in 180 grams of carbohydrates per day (assuming a daily protein requirement of 135 grams). This dramatic difference between the carbos recommended by Dr. Colgan and those recommended by Dr. Sears leads me to the conclusion that the 40-30-30 diet may leave an endurance athlete subject to chronic glycogen depletion if they strictly follow the guidelines in Sears' book.

As for the other benefits of the 40-30-30 diet, I think that Mr. Sears has done a major service in bringing to light the importance of adequate protein consumption, the pitfalls of consuming high glycemic carbohydrates, and the importance of adequate high quality fats in the diet. My personal "macronutrient strategy" consists of consuming lots of carbs when training, mostly in the form of Cytomax, Accelerade, Gu, etc..., and a fairly high-carbohydrate recovery drink with some protein right after training (in the form of Endurox R4 or Ultragen). Outside of training I try to maintain a more balanced protein/fat/carbo ratio with each meal and snack to minimize blood sugar fluctuations and to make sure I get adequate high quality protein.

Ultimately everyone should determine what works best for him or her through experimentation and observation. Some Personal Best Nutrition customers have told me that on ultra long workouts and races (such as the Ironman and double Ironman distances) they do better consuming fat and protein in addition to carbohydrate. As an endurance athlete you know how to listen to your body, and you should trust what it tells you.

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