Prelim Review of New Scales

We just bought a fairly expensive ($80-something) set of Tanita scales that measures bodyfat and percent water.

So far, I'm disappointed. Is there a trick to taking consistent measurements with these things? I'm curious if others have decent results.

It ranges from 7.8% to 10% depending on the time of the day. It has a general trend of lower percentages as the day goes on, but even that's not consistent. There's also the question of whether or not to use "athlete" mode and it makes a whale of a difference, like from 8% to 16%.

The percent water is inconsistent also. One day, I hadn't had a drop of water all day and ate several large meals, and it read the highest of all the days so far! The other days, I was very hydrated and it read about 5% less (59% vs 64%).

I think I need to plot the results and try to identify a pattern.

Edit: I do think the scales are very accurate at weight measurement. I just took a reading and then, umm, suddenly decreased my water content, and it had me 0.4 lbs lighter. It seems to read correctly and does not change readings if I rock forward or backward. The bodyfat measurement seems sensitive to water loss also. It went from 8.9 to 9.2 on these two measurements.

DBD

 

DCalJackD:

"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."

That's their definition, but it's not that helpful for me. I do not work out for 10 hours/week but my resting heart rate is typically below 60 bpm. I have remained fairly muscular for years, but not overly so, and have only worked out on-and-off for the last 10 years. I was a competitive lifter and judo player, but that was 10 years ago. The calipers predict 9.5%BF. If I use "athlete" mode then the scales read anywhere from 7.8% (evenings) to 11%BF (mornings). In normal mode, they say 16%-19%BF. I can barely pinch fat anywhere and am in 32 jeans, so I don't believe 16-19%, so I've stuck with "athlete" mode so far, even though it's a troubling classification for me. I think I can loosely classify as "athlete" using their last sentence. Geez, this is like reading a building code.

I think it's amazing how much weight is lost during sleep. The last 2 days, it's been over 4 lbs. I assume that water loss is the source.

As for BF, they always read higher in the morning and I can kinda see a pattern, but it's not the same every morning or evening. Food intake seems to make a huge difference. The presence (or absence) of a couple of pounds of food is bound to make a difference because it has some electrical impedence, which is what the scales use.

DBD

 

I assume that the scale just spits out a number from an equation based on a multivariable curve fit using age, height, weight, and electrical impedance (the input parameters plus the measured parameter).

The researchers developing the method probably saw a big difference in their test subjects who fell into those two loose categories, athlete vs normal dude, so they developed two equations.

These ended up programmed into the scale. It would be interesting to know if they two results are correlated, but that would take too much work.

DBD

 

That's funny, kinda like in the Green Mile.

It is somewhat consistent at the same time of day, probably within 1%.

DBD