Archive for the 'Bod Pod' Category

Bod Pod: Worthless in the Hands of a Boob

Mike on Oct 1st 2010

What I learned yesterday: the Bod Pod is a $40,000 piece of junk if the operator doesn’t know what he is doing. Recently I blogged about my experience in the Bod Pod, getting my body fat percentage measured. It is highly accurate, state-of-the-art, and has a margin of error similar to Hydrostatic Weighing (the gold standard of body composition testing). The only problem is, all of that is utterly wrong if the person operating it is a boob. What I didn’t mention in my earlier article about the Bod Pod was that while I was sitting there in my underwear waiting to be tested, the technician kept putting a cylinder into the pod, taking it out, putting it in, taking it out, and on and on at least half-a-dozen times, trying to calibrate the pod. He mumbled to himself constantly and then at one point said, “I’m afraid we might have to reschedule you because I can’t get it to work right…no one set it up this morning and it won’t let me continue.” Then he picked up the phone, made a quick call, and after about 15 seconds on the phone said, “What? It’s okay? Uh, okay.” Then he hung up the phone, cancelled out of the computer screen he was on, and started my test.

The results showed that I was at 44.9% body fat, which was 122 lbs of fat and 150 lbs of lean body mass (LBM). I was encouraged by the amount of body fat it meant I had already lost, but it was also disappointing because it meant that I still had something like 100 lbs more to lose. It really didn’t sound right to me, because that meant I should weigh in the 160s, which didn’t seem possible, but hey what do I know…I can’t argue with the Bod Pod, right? I assumed underneath all that fat I just wasn’t as muscular as I thought. So, I went on my way thinking I had a very long way to go. Fast-forward six weeks to my testing myself with a cheap, $35 bio-impedance analysis (BIA) monitor and a cheap set of skinfold calipers. The BIA monitor said I was 33.1% body fat and the skinfold calipers had me at 33-35%. Well, those HAD to be wrong! I mean, I was tested in a freaking BOD POD, man! The only problem was, when I started plugging hypothetical numbers into the skinfold caliper measurements (assuming I had measured wrong), it was impossible to get myself up to even 40% body fat, much less up to 45% to match the results of the Bod Pod analysis. Then I thought back to the operator’s “uh, okay” phone call and got very suspicious that he had screwed up my test.

My solution was to call the renowned Cooper Center in Dallas and schedule an appointment for hydrostatic weighing. Then I’d know once and for all, because it is the gold standard test that all the others are judged by, and because the Cooper Center most definitely knows what they are doing. They also do skinfold caliper measurements at the same time for comparison. It was an odd experience to say the least, but I’m glad I did it, because the underwater weighing put me at 33.3% and the skinfold calipers put me at 33.6%. That’s fully 12% below where the Bod Pod had me, and it means I need to lose between 46 and 70 more lbs rather than 87-107 lbs, depending on how low I want my body fat percentage to go (i.e. 9-19%). Rather than having a LBM 0f 150 lbs, I’m at 177 lbs. That’s 27 more lbs of muscle than the Bod Pod said. Quite a difference!

One final point. To be fair, I can’t call the operator a boob, because he was just doing what he was told. The boob is the person on the phone who, after a 15 second conversation, told him everything was fine and to do the test on me anyway. In the end Louanne called the facility and talked to the manager about it, and they’ve agreed to repeat the test for her next week for free. Go Louanne! They said they’ll test me too, but I don’t really care since I was just tested at the Cooper Clinic yesterday. What’s the point of another test, other than giving them the chance to prove to me that they might be able to get it right this time.

Below are some photos from yesterday. Click any image to see a larger version, or you can view the whole album on the Photos page.


First they took measurements at seven different points using skinfold calipers. If you ever have this done, get ready because they have to pinch you pretty hard to do it right.



When you do the test you have to exhale ALL the air out of your lungs while you are holding yourself completely under the water, then pause for a few seconds trying to be as still as you can. You have to do this several times. Some people can’t handle it because they feel like they are trying to “voluntarily drown themselves.” I had no problems with it, but I can completely understand why it might freak some people out. Louanne said after watching me she will NOT be doing it. I’ll probably repeat the test every six months or so.

Filed in Bod Pod,Body Composition,Hydrostatic Weighing | 8 responses so far

The Bod Pod

Mike on Aug 20th 2010

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.

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.

Filed in Bod Pod,Body Composition,Encouragement | 11 responses so far