4 minute read
Adjustments
To best understand the Zone Diet, CrossFit athletes should read Dr. Barry Sears’ book “Enter the Zone.” This article gives more information regarding block prescriptions and fat adjustments for CrossFit athletes.
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The chart based on sex and body type in the article “Zone Meal Plans” is perfect for those who want to start the Zone Diet. If the athlete chooses the wrong block size and does not obtain the desired results, the plan can be modified after a few weeks. Errors in block selection might slow progress, but initial errors are offset by the huge value in starting a practice of weighing and measuring intake.
Sears details a more precise method to calculate one’s block prescription in “Enter the Zone.” It is: Zone block prescription = lean body mass (lb.) x activity level (g/lb. of lean body mass) / 7 (g protein/block)
The activity level ranges on a scale of 0-1. For those who work out several days a week and do not have a labor-intensive job, the activity level should be 0.7 (most CrossFit athletes). By dividing 0.7 by 7 g in the equation, this simplifies to a Zone block prescription that is 10 percent of his or her lean mass.
The activity factor should increase if the athlete does CrossFit two or more times a day, trains for another sport in addition to CrossFit, or holds a strenuous daily job (e.g., construction, farming, etc., and potentially coaching, if on one’s feet all day). Although CrossFit workouts are relatively intense, they are not long in duration. An individual does not need to increase the activity level value based on intensity alone; activity volume determines activity factor.
Sample Calculation of the Zone Block Prescription Suppose an athlete is 185 lb. (84 kg) with 16 percent body fat. He does CrossFit five days per week and works in a typical office environment. A sample calculation of his Zone block prescription follows.
First, lean body mass is calculated (calipers are a convenient, easy-to-use, and reasonably accurate method): lean body mass = 185 lb.–(0.16 x 185 lb.) = 185 lb.–29.6 lb. = 155.4 lb.
Because the activity factor is 0.7, the simplified formula is used: block prescription = 155.4 lb. x 0.10 = 15.54 or ~15 blocks
This means that the example athlete above would eat 15 blocks per day (Table 1).
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Protein 15 blocks x 7 g = 105 g (420 calories)
Carbohydrate 15 blocks x 9 g = 135 g (540 calories)
Fat 15 blocks x 3 g = 45 g (405 calories)
Total Calories = 1,365
Note the total calories presented here are underestimated due to hidden calories. Most foods are classified by a single macronutrient, despite the presence of some other macronutrients (e.g., nuts are classified as a fat but have some protein and carbohydrate calories). These less predominant macronutrients for each source are not included in the total calorie calculations.
This athlete could also choose to round up to 16 blocks, particularly if he or she is more likely to have compliance issues. The Zone prescription is a calorie-restrictive diet and can be especially difficult for new adopters. When one’s calculation has a decimal value, rounding up to the next whole block might result in slower progress but produce better long-term compliance. Once the athlete has become accustomed to the diet, then the total blocks can be rounded down to 15, particularly if desired body composition has not been achieved.
Increasing Fat Intake The caloric restriction leans out the athlete while providing enough protein and carbohydrate for typical CrossFit activity levels. However, the athlete can become too lean. The athlete is considered “too lean” when performance decreases in combination with continued weight loss. “Too lean” should not be based on body weight or appearance alone. When a loss of mass coincides with a drop in performance, the athlete needs to add calories to the diet. This can be accomplished by doubling the fat intake (Table 2).
Protein 15 blocks x 7 g = 105 g (420 calories)
Carbohydrate 15 blocks x 9 g = 135 g (540 calories)
Fat 30 blocks x 3 g = 90 g (810 calories)
Total Calories = 1,770
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At twice the fat, the macronutrient ratio based on calories has changed from 30 percent protein, 40 percent carbohydrate, 30 percent fat to 23 percent protein, 31 percent carbohydrate, 46 percent fat. Fat can continue to be multiplied if the athlete experiences further mass loss and performance decline. Some CrossFit athletes have a diet including five times the fat (Table 3).
Protein 15 blocks x 7 g = 105 g (420 calories)
Carbohydrate 15 blocks x 9 g = 135 g (540 calories)
Fat 75 blocks x 3 g = 225 g (2,025 calories)
Total Calories = 2,985
At five times the fat, the macronutrient ratio based on calories has changed to 14 percent protein, 18 percent carbohydrate, 68 percent fat.
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