We’re just past the midway point of our Whole 30 challenge (Day 19), and I’d like to applaud the participants for their dedication and innovative ways to keep their menus constantly varied. One of the deciding factors for the winners of the challenge is a [positive] change in body composition. The trainers will take before & after photos and pick out most improved, but we’re also looking at bringing in mobile hydrostatic body fat testing near the end of the month.

There are a few common (and some less common) ways to test body fat (BF). One of the cheapest and readily available ones is the caliper method where a trained professional takes measurements of areas on your body where fat would be deposited and calculates your BF% based on your body weight. Its accuracy greatly depends on the expertise of your technician and quality of the caliper.

The hydrostatic method is widely accepted as a rather accurate BF% measurement and is relatively affordable. A technician weighs you first, the you are submerged and weighed underwater. This test depends on the fact that muscle, bone, and connective tissue weighs more than fat and will factor into a calculation with your land weight for your BF%. Basically a 200# man with 5% BF will weigh more underwater than a 200# man with 20% BF.

One fault with this method is potential operator error. It depends on the testee’s ability to be comfortable enough underwater to blow out ALL the air in their lungs and remain submerged long enough for the technician to read the weight on the scale (~1 second). I can personally attest that the test is painless and everyone who knows me knows about my issue with water!

The Bod Pod is similar to the dunk test but you sit in a tiny space and the machine measures your air displacement in a similar way the hydrostatic method measures water displacement. Upside is no submersion; downside is claustrophobia.

The most accurate method is so difficult to get access to, it’s almost a holy grail. The DEXA (Dual Energy X-Ray Absorptiometry) uses low dose x-rays that read bone and soft tissue mass. It can take between 10-20 minutes and you have to lie still for the entire thing. It’s found mostly in orthopedic doctors’ offices for the purpose of measuring bone density and is pricey even if you do find one.

All this information comes with a huge caveat. We at CFI do not want to make it your goal to have as little body fat as humanly possible. Yes, we want you to have lean body mass. Yes we want you to not hold excess fat. However, every athlete will have a different “optimum” BF%. Some studies show that having some BF can help with recovery.    Simply put: Male Athlete A may function best at 4%BF while Male Athlete B functions best with 10%.

If you are leaning out and find that your performance is sluggish and you can’t seem to recover from workouts as efficiently (and your sleep, nutrition, and training days have remained consistent), consider regaining that 1-2% that puts your body in a more efficient state.  If you participate in sports outside of CFI, you may also consider optimum body frames for that sport.  Just as we don’t want you to sacrifice form in a WOD in pursuit of a PR, we don’t want you to sacrifice your fitness in pursuit of a zero BF bod.

If anyone is interested in getting tested via the hydrostatic method, we may have them bring out a mobile testing device to us on April 30th, the day of our in-house power lifting meet.  Please post to comments if you want to be tested.  I’ll check on the price but I believe it was between $50-60 per person.  We’ll need to drum up a minimum number of people to have them come out.  We’ll be asking for interested people to pay in advance to reserve their spots.

WOD 04.22.11


  • 5 Power Cleans (145/100)
  • 10 Toes to Bar
  • 15 Wall Ball Shots (20# 10′/14# 9′)

Pallof Press 3×3 (each side)

9 Responses to “Eureka!”

Michael H
April 22, 2011 at 8:22 AM

Count me in!

April 22, 2011 at 8:46 AM

Sorry Mike. You don’t have enough fat to measure. :)

Anyone been watching the NBA Playoffs on TNT? (Do I sound like a commercial?) Anyone catch Charles Barkley’s comments Wednesday night? He was talking about the halftime show for the Lakers game – a couple of Cirque du Soleil acrobats were doing crazy contortions – and he said “I’ll have to talk to my Crossfit people so I can get my core strong enough to do that!” WHAT?!?! Did Chuck just say he does Crossfit? Apparently that was the second time he mentioned Crossfit this week!! CRAZY!!


April 22, 2011 at 9:55 AM

Yes! I want to dunk! I did it April 2nd so it will be a perfect time to see my results through the paleo challenge!

April 22, 2011 at 10:23 AM

Ignorance is bliss ;P I’m kind of on the fence about this one and not sure if I want to know or not. Given my intrepidation, I won’t commit, but I’m definately going to be there on Saturday to either compete or cheer on the homeys so it could definatley be a game time decision.

I find I often agree with Charles Barkley…this is just another instance.


April 22, 2011 at 10:49 AM

In for dunking. Go Charles Barkley. Eff the Lakers. That is all.

April 22, 2011 at 11:38 AM

Count me in too!

April 22, 2011 at 1:41 PM

Why so angry Marcus? Is it because your team is not in the playoffs?

April 22, 2011 at 1:51 PM

Oh, but my team is in the playoffs. The Red Wings swept their first round series. :)

April 22, 2011 at 7:36 PM

And Marcus is a Spurs fan! :)