Metabolism

This past Saturday, I spent the better part of the afternoon promoting Cahaba Cycles at Alabama Powerman. While at the Cahaba tent, I struck up a conversation with Kristy Harris of FitnessWave. The details are on their website, but they basically perform VO2 max testing, hydrostatic body composition testing, and metabolic rate testing. Despite my background in elite level swimming and engineering, I have never been a big “numbers” person when it comes to exercise. I just got my first HR monitor last year! However, I couldn’t help but gain curiosity when I saw them doing a metabolic test on a volunteer. In order to complete the test, you must first go at least four hours without eating or drinking anything other than water. Then, you sit down, put on a nose clip, and breathe into a tube attached to a machine that measures your resting metabolic rate (RMR). This represents the calories the body burns to maintain vital body functions (heart rate, brain function, breathing, and other essential activities). In simple terms, it is the number of calories a person would burn if awake, but resting all day. With an empty stomach, I completed the test and gained some insight into why so much of my family budget goes towards groceries. As I learned from the test, my body burns 2232 calories/day just maintaining vital functions. From this, they were able to estimate that I burn an additional 669 calories/day doing everyday chores (walking up stairs, brushing teeth, etc.) and 279 calories in a half hour of moderate exercise. It takes a VO2 max test to determine the exact calorie burn for different levels of exertion. However from these results it’s entirely reasonable to assume a 4000+ calorie typical day for my training schedule. Of course this number could easily be 50% to 75% higher on a big training day. For anyone trying to ensure they are getting the right amount of calories to stay fueled, or to gain, maintain, or decrease weight, a metabolic test is a great way to establish some baseline individualized data.