T Nation

Body Fat

Had my body fat measured at the gym today. They used a handheld electronic device made by I believe Ormon. I think it read a little high at 13.3%. I believe I am more about 11%. But I could be wrong and do not really care. I am just curious if these thing are decient at reading bf. I had to enter my weight,height and age into the little machine.

Anyone have any experience with these?

Solo, I’ve had a good deal of experience with them. From what I can tell, they’re trash:-) Seriously. They’re reliable in that they give consistent readings over trials and over days (in the same subject), but the readings are inaccurate! So, it’s a consistently invalid tool of measure!

If you took the measurement after your workout, it’s likely that you were dehydrated. In the event that you’re not adequately hydrated, you’ll get an overestimation of percent fat.

Having said that, I actually find that these electronic devices often underestimate percent fat.

The best gage for body fat is in a hydrostatic dunk tank. I may be preaching to the quire but let me explain.

  1. You are weighed outside the tank
  2. Your lung volume is measured (it helps with the measurements)
  3. You are then dunked and asked to expel all the air from your lungs (this weighs you inside the tank under the water)
  4. Next the person testing you runs this info into a database which lets them know what your body-fat percentage is. It is accurate down to around ? of a body fat percentage.

I am fortunate enough to go to school where I have this available to me and get it measured every three months to check progress. If you can locate someone who does this maybe at your local university you can do the same and use it to judge your training on a personal level. You may have trouble locating a dunk tank but look around at sources around you.

If I did not have this to use, I would use both the electric impedance and skin fold. By using both of these you can average the two getting a more accurate result.

Hope this helps

Thanx Timbo. I did have it measured after my workout. So now I will look for another method.

They’re also notoriously inaccurate when used to measure males with above-average levels of muscle mass and single digit bodyfat. Apparently, the calculations involve some sort of standardized “reference body,” with the result that a 5’6", 185-lb male with six-pack abs and pretty good vascularity on the arms and shoulders will measure out at 16-17%.

Those things suck.

So does the dunk tank.

Another problem with them is because they’re electronic they become alter with sweat composition. So your best readings are going to come at the first thing in the morning and with no sweat on your body. Those Tana scales are similar and I’ve seen them over-estimate bodyfat so badly that a marathon runner with some of the best abs I’ve ever seen was marked at 29%. They don’t always overestimate (often underestimate) but it’s really a crapshoot.