Friday, June 7, 2013

I Got Tested (A Bod Pod Experience)

I've been working with a nutrition coach who specializes in athletes and the first thing he recommended doing was to get my body composition tested.  Previously, I've tracked body fat using both calipers and BIA (those bodyfat scales you can use at home) and they both suck.  Calipers require a high degree of skill to use and only measure subcutaneous fat.  Even with an experienced tester, the margin of error is around 5%.  BIA has a margin of error around 8% and is greatly influenced by hydration levels.  Depending on the machine you have, BIA also only measures your lower body fat (scales) or your upper body fat (handheld devices).  Not to mention that you aren't supposed to consume caffeine for a week prior to BIA testing.  Eff.  That. 

For example, I would wake up and get on my fancy bathroom scale and get a reading of 40%.  I'd then use my handheld Tanita device and get a reading of 30%.  Then I'd go to the gym and one of the trainers would measure me to be 22% and another would measure me at 32%. 

I always told myself that it didn't matter what the actual numbers were; the trend is what was important.  But it's hard to see a trend when the margin of error is greater than the change.  (Did I really lose 5% body fat or is that part of the +/-8%?)

So anyways, my coach advised me to get a Bod Pod measurement.  Bod Pods have a 1% margin of error, which is similar to underwater weighing and DEXA scans, but is cheaper and easier.  Plus, being repeatedly dunked in water or bombarded with radiation just isn't my thing.  Google told me that a local university had a Bod Pod, so I called and made an appointment for Jason and I for that same week. 

Photo from

I was told to wear tight fitting Lycra shorts and a sports bra for the testing and not to eat or exercise for 3-4 hours before the test.  They said that normal hydration was okay, but I had read elsewhere not to drink anything 2 hours prior to the test. 

We got to the testing lab, donned a stylin' swim cap, and got weighed.  Then we sat in the Bod Pod, a big egg-shaped chamber that looked like something out of a B-list Sci-Fi movie.  The tester (who was a grad student in the Human Performance Lab) ran two tests with us just sitting in the machine.  We sat there, perfectly still, for about a minute while the pressure was changed inside the machine.  It wasn't uncomfortable or anything, but my ears felt a little funny.  Then, he repeated the test with us breathing into a tube so he could account for our lung volume.  This part was a little tricky.  The machine required us to breathe at a certain pace and then huff at the end.  Jason took three tries.  I, however, am excellent at breathing and nailed it on the first shot. 

We got dressed and got a printout of our results.  All to the tune of $25, each.  It took less than 30 minutes from start to finish.  

Now about the results...  it is what it is.  As I said, my body fat numbers have been all over the place each time I've been tested before, so I really didn't have a certain number in my head.  These results are really just a starting point for my journey with my new coach.  I'll test again in 3 months and all that will matter is that the number goes down. 

This link will give you all the science of how a Bod Pod works (pdf). 
This link will take you to a Bod Pod site locator. 

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