Tuesday, November 13, 2007

Recent Question about CrossFit

Dear Reader,

Thank you for your recent question about CrossFit, a popular workout program in elite fitness circles.

CrossFit workouts are incredibly demanding and, according to the CrossFit website, “tax the capacities of even the world’s best athletes.”

Momentum Nutrition and Fitness cannot endorse any particular fitness program without meeting you, but we can provide you with a few tips when choosing a program that meets your needs.

1. Are the personal trainers or coaches certified by reputable institutions?

Something to think about: To become a certified CrossFit “coach” the fee is more than 4 times the amount required by the ACSM and the NSCC, the gold standards in fitness training.

2. Does the program recommend supplements over food?

At Momentum Nutrition and Fitness we strongly believe people can get all the energy they need for daily living and even demanding workouts from food. For situations that may warrant a supplement, refer to the November 8 posting.

3. If the program offers nutritional guidance, is it being provided by a registered dietitian?

Something to think about: CrossFit endorses caloric restriction and the following caloric percentages from macronutrients:

30% calories from protein
30% calories from fat
40% calories from carbohydrates

Evidence based literature on sports nutrition tells us that athletes need at least 55-65% of their daily intake from carbohydrates (to prevent glycogen depletion which can jeopardize performance), 15-20% calories from protein, and 30% from fat. These percentages are similar for sedentary to mildly active people (with 55% intake from carbohydrates being sufficient to sustain daily activities).

Caloric restriction, especially in the setting of rigorous activity, can have several consequences. Here are a few:

-Lowered metabolism
-Muscle loss and fat conservation
-Altered immune function leading to increased sickness
-(In women) Irregular or absent menstrual cycle which can lead to bone loss and, sometimes, fractures

-Increased urges to binge eat
-Reduction in work output of heart

If you're interested in calculating how much energy you need from food, see yesterday's posting.

Thank you, again, for the great question!

Contributed by Monica Van Winkle, MS, RD

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