Device that Measures Body Fat %

Don't quote me but I think it is +/- 7% accuracy.

It is a bioimpedance analyzer, easy to use but not to accurate.
Electrical resistivity is based on the fact that muscle and fat vary in
the amount of resistance they have to electrical flow. Measurements are
made by placing one or two electrodes on the body. The test is HIGHLY
dependent upon the body's state of hydration, such that dehydration leads
to an inordinately high body fat reading.

This is what Lyle McDonald says about it:
"Yes, BIA measurement of body fat is total crap. It's highly, highly
dependent on hydration state. Go in hyperhydrated (i.e. eat salt the
night before) and it gets totally screwed up. Go in dehydrated and it
gets totally screwed up. It's only benefit is that it's fast and any
idiot can run the machine."
 
It's just like the Tanita scales, only that they are handheld. They both use Bioelectric Impedance Analysis, they send a weak current through your body and because fat and lean mass have different conductivities they can estimate BF percentage. If you use them at the same time of day, same level of hydration, sleep, exercise, etc they can be consistent. As for accurate, it depends on the person. They estimate total bodyfat and you have to also enter your age. This is because as we age we generally store more visceral fat. But it is the subcutaneous fat that determines how lean you look. That is, if two identical persons of 20 & 35 years are both 10%, chances are that the 35 yo will look more cut since he will have less subcutaneous fat. Calipers measure directly this subcutaneous fat, while BIA devices estimate both subcutaneous and visceral fat.
 
So overall its good but only if I use it always at the same time. i.e. Right after a work out on an HST day before I drink my post workout shake. (This is when I did it the other day).
 
I have one of the T scales and have found it quite consistant... True, maybe I should check it else where, but I've only had a couple major BF fluxes and that was usually after a gorging session =)

I believe the ideal rules to follow for the bioimpedence devices is:
-3 hours after eating and waking
-Same time (possibly between 5-7 PM?)
-Urinate before reading (at least within 30 minutes)
-Don't drink with in (+?)30 minutes of reading
-Clean feet or hands and electrodes
-Lock knees and stand up straight

I follow these rules and seem to get a consistant reading. I used mine on my last cut that went from 22%-12% BF according to the scale. Perhaps I don't have as many troubles becuase my diet is usually quite regular, my hydration is usually either normal or high, and I try to stick to those rules...

Based on these rules, you might want to change your check time. Or, even better, you could try it when you were doing it then test it at a different time that follows the above rules - See if there is in fact a huge difference. I usually work out in the morning, plan my last lunch of the day before I get out of work, and weight before supper. That usually nails all the criteria =)
 
When I use it, I do so every morning after I pee, then I average a week's results. It's this average that I weigh up.
 
[b said:
Quote[/b] (micmic @ Mar. 15 2004,3:49)]When I use it, I do so every morning after I pee, then I average a week's results. It's this average that I weigh up.
Click to expand...
Same here, and I've found this to be a dependable measure of progress. It may not be correct in terms of the absolute value it reads out, but if you are losing fat the readings do go down predictably.
 
You must log in or register to reply here.
Back
Top