I’ve had access to a scale that calculates body fat this week and have been playing with it and it has been an interesting experiment. (Susan, I’ve been thinking of you… since your body fat was measured at the gym using Bioelectrical Impedance Analysis, which is the same technology as the scales use.)

I could lose 2 fat percentage points just by going pee. I was 22% fat with a full bladder (and it wasn‘t even bursting full…) and 20% fat after going pee. Although, according to the scale manufactures… I should have seen my fat % go up… not down.

This scale (and the hand held device I used at the gym) have an “athlete” setting and a “normal”. I've seen an “athlete” defined as someone who exercises or is "active" or does “physical work” 10 hours a week. A “normal” person (according to the scale mfr) may do zero exercise.

With the scale on “normal” I’ve gotten a reading as high as 25% fat. On “athlete setting”, I’ve gotten a reading as low as 18%. I’m guessing that someplace in the middle is accurate.

I’ve read recommendations online… to weigh yourself on a scale twice a day for a month and then average the 60 scale readouts.

Getting tested one time in a gym… might not give you an accurate percentage.

I took Covert Bailey’s book, “Ultimate Fit or Fat” and he’s tested the body fat of thousands of people using a dunk tank and claims that he has a tape measure method that is within 2% accurate for most people…

http://www.healthcentral.com/cholesterol/home-body-fat-...74-143.html#accurate

Using his method, I got a body fat of 20%… or with his 2% margin of error… 18-22% fat… which is pretty good. Happy with that.

quote:

Originally posted by Sheltieguy:
Things that can affect hydration include:

• strenuous exercise

• recent food intake

• diuretics such as caffeine, alcohol, certain medications

I was also thinking that for women... different days of the cycle probably affect "hydration".

quote:

Originally posted by GoingSkiing:
[...]He used a hand held thing... that was basically a mini Tanita scale that you held in your hand... And he programmed it and put my age, weight, and height into it. I suppose the bioelectrical thing went thru my arms to my body... instead of thru my legs to my body. I didn't give my level of hydration or anything a second thought.
[...]

That sounds a lot like what they use at Curves. My numbers are in the 40's but they have come down since I started at Curves.
One advantage to that is that I don't think I could drown if I tried. When I am in the pool I float. I don't have to "tread water" to keep my head above the water level. I just curl my legs up under me as if I am sitting "indian style" and move my arms on top of the water the way you do when treading water and I just float.

quote:

Originally posted by susanrows:
Where do you have access to this device? Do they have one in your gym?

I was tested at our Y in June or July 2005... when I had finished up rehabing and PT for my knee... and I had 3 sessions with a personal trainer. So it was before I had really started lifting weights... but I had been exercising.

He used a hand held thing... that was basically a mini Tanita scale that you held in your hand... And he programmed it and put my age, weight, and height into it. I suppose the bioelectrical thing went thru my arms to my body... instead of thru my legs to my body. I didn't give my level of hydration or anything a second thought.

At that time, I tested at 23.something percent fat. And I distinctly remember him asking me "Normal? or Athlete?". I told him "normal", since... ummmm, duh... I'm not an athlete... Although I suppose that I meet Tanita's "athlete" definition some weeks a year.

I strapped on my HR monitor (today) and went and lay down for 11 mins at 5:30pm. When I first lay down… my HR was 70 and the lowest number I saw was 59. The average for the 11 mins was 65 (I also have the BP of a dead person).

I’ve had 12 oz of coffee… and about 36 oz of black tea with caffeine. And I lifted weights for 25 mins and did the elliptical (really hard, today) for 35 mins at 1:30pm. I was also really hungry and multi tasking and napping while hard boiling eggs for a sandwich, so I was having trouble relaxing as my stomach would growl every now and then. Don't know if all of that affects my "resting" HR.

But, I just wanted you to know that in the past 3 days… I’ve played with the scale at different times of day… and different “normal” and “athlete” settings… and me personally, I’ve gotten reading from 18% fat to 25% fat. So… take the ONE reading you got with a grain of salt.

Even getting tested at the Y again, I’m not sure exactly how much my body fat has gone down… and I don’t really know if I could 100% reproduce that EXACT same hydration level as I had one day in 2005... So a different number might not mean anything.

Thanks for thinking of me, Denise. I have read Covert Bailey's books and done his tape measure body fat calculation. Seems to me I came out in the low to mid-20's, but I would have to get out the book and see what I wrote down.

I also remember that he said there were ways to affect your results in the dunk tank -- like eating a big meal right beforehand or "sewing lead weights to the inside of your bathing suit."

And according to Tanita's definition, I'm not an athlete either, although I suppose I knew I gave up that moniker when I gave up rowing.

Where do you have access to this device? Do they have one in your gym?

quote:

Originally posted by Sheltieguy:
Tanita defines "athlete" as a person involved in intense physical activity of approximately 10 hours per week and who has a resting heart rate of approximately 60 beats per minute or less.

I ski 10 hours a week sometimes. Does that make me semi athletic?

I think that my hr is about 60 (if I switched to decaf ). Hopefully, I can lay down for a nap later... will let you know.

From Tanita, the maker of BIA Body Fat Percentage scales:

"Q: Are there optimal conditions for determining body fat percentage using Tanita's products?

A: Yes, there are:

Select a consistent time of day, and stick to it.

With an empty bladder

When normally hydrated

Unclean foot pads may interfere with conductivity.

Nylons interfere with conductivity. If it is absolutely necessary to measure in nylons, use a drop of isopropyl (rubbing) alcohol on the foot pads to act as a conductor.

Things that can affect hydration include:

• strenuous exercise

• recent food intake

• diuretics such as caffeine, alcohol, certain medications

Early morning is not recommended because the body is often dehydrated after a night's sleep. Once you have established your baseline, monitor body fat about twice a month. Checking body fat more frequently is not beneficial as changes occur slowly over time."

"Q: How accurate and reliable are Tanita's Body Fat Monitor/Scales?

A: Independent research at several major universities (including Columbia University in New York City) has confirmed that in clinical settings, the Tanita Body Fat Monitor is accurate within +/- 5 percentage of the institutional standard of body composition analysis--Dual Energy X-ray Absorptiometry (DEXA). It should be made clear that there is only one method of calculating body composition that is close to 100% accurate, and that is an autopsy. Tanita believes its method to be the most convenient and accessible to accurately predict body composition. Tanita's Body Fat Monitor Series results are repeatable to within +/- 1 percent variation when used under consistent conditions."

"Q: Why is there an "Athlete Mode"?

A: The Athlete mode was developed to provide a more accurate reading for athletic body types. Athletic body types are physiologically different than standard adult body types, due to muscle mass and hydration level differences. Athletes tend to have greater muscle mass and tend to be more dehydrated. These differences would skew the body fat reading high, when taken with the standard Adult mode.

Tanita defines "athlete" as a person involved in intense physical activity of approximately 10 hours per week and who has a resting heart rate of approximately 60 beats per minute or less.

Tanita's athlete definition includes "lifetime of fitness" individuals who have been fit for years but currently exercise less than 10 hours per week. Tanita's athlete definition does not include "enthusiastic beginners" who are making a real commitment to exercising at least 10 hours per week but whose bodies have not yet changed to require the Athlete mode."

More at:

http://www.tanita.com/FAQ.shtml