MikeIsLosingIt.com

UPDATE: Since posting this article several weeks ago I discovered that my Bod Pod analysis was incorrect…it was so far outside the margin of error that you could easily call it ridiculous. For an update on the Bod Pod and my experience with hydrostatic weighing, see my post: Bod Pod: Worthless in the Hands of a Boob.

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The Bod Pod is a large egg-like pod that is used to measure body composition. After being analysed about a month ago in one of them, I now know what it would feel like to be some kind of giant bionic chicken, or maybe one of the astronauts in 2001: A Space Odyssey before HAL 9000 kills them…or better yet, fat Jonathan Winters in Mork and Mindy.

When my Tanita scale at home isn’t telling me “Error Error Error,” it’s giving me readings that fluctuate wildly from 40-46% body fat. That’s a huge difference, and it gives me similarly conflicting readings for lean body mass. Consequently I’ve gotten tired of not really knowing for sure where I stand in my fitness program, so I decided to get a professional, non-bio-impedance test to give me a reasonably accurate estimate of my body fat percentage and lean body mass. That would give me a good benchmark from which to set reasonable goals and track my results.

I did a lot of research and found that the most accurate tests are hydrostatic weighing (underwater weighing), DEXA (a test using x-ray technology), and the Bod Pod (air displacement plethysmography). The Bod Pod is similar to underwater weighing except that it measures the volume of air you displace rather than water, making it MUCH more convenient and just as accurate. I could only find one place in Fort Worth that has one, the City Club of Fort Worth. Fortunately you don’t have to be a member to use it, but you do have to pay $50. There is a cheaper place about 45 miles away in north Dallas, but the City Club is about 10 minutes from us, so the choice was a no-brainer.

The process is very quick and simple. You have to wear something tight like compression shorts and a swim cap, because your hair and loose clothes can trap air and throw off the readings. They weigh you, you sit in the pressurized pod for about a minute (you don’t feel any pressure changes), and you’re done. Couldn’t be easier. I plan on doing it once every few months or so to track my results. My research says that the Bod Pod has only a 1-2% margin of error, similar to the other “gold standard” tests. Here are the numbers from my test:

Body Mass: 272.189 lb
Fat Mass: 122.249 lb
Fat Free Mass: 149.939 lb
% Fat: 44.9%
% Fat Free Mass: 55.1%

So after about five months of training with three months of dieting I’m down about 50 lbs, with a body fat percentage of 44.9%. I wish I knew exactly where I was when I started, because I KNOW I’ve gained muscle/lean body mass, which means I’ve actually lost more than 50 lbs. But, just so that I’d have a reasonable idea, I ran the numbers to calculate what my minimum body fat percentage was when I started by assuming I haven’t gained any muscle at all. I know I’ve gained some (probably quite a bit), but at least this gives me a minimum starting point. At 321.6 lbs, with 149.9 lbs of lean body mass, that puts me at a minimum of 53.4% fat when I started. If I’ve gained say 10 lbs of muscle (which is probably still a conservative guess), then that would put me at 56.5% fat at the beginning.

All of that means that I’ve lost somewhere in the neighborhood of 9-12% body fat since I started. Pretty cool. Yes, I’m still at 44.9% fat, which is hugely obese, but I’ve come a long way and am very encouraged. My hope for the next time I’m tested is to have gained several pounds of muscle while losing 20-30 more pounds of fat. I’ll probably go again sometime shortly after breaking the 250 barrier.

Below is a scan of the test results with several more stats listed, such as my Resting Metabolic Rate (RMR). Click the image to see a larger version.