Body Fat % Fluctuations, What's up with that?

oeagleo

I have over the last year lost close to 100 Lbs, and now need to "tone up", or whatever the PC term is for getting rid of my bat wings. Bat wings, on everything I own, arms, legs, belly, chest, etc. I've recently joined a gym, as I don't have the right equipment to do this at home, and am really enjoying my workouts. I work out with weights 3 days a week, each session concentrating on a specific body area, (arms/chest one day, legs/abs another, and back/shoulders on the third), with cardio on the days in between, cardio being 30 or so minutes on the elliptical with planks, and back hyperextensions for core. Now, I'm feeling great, and I believe it's taking effect, but the one thing that has me puzzled, is that on some days, while my weight may stay the same, or lower, the body fat percentage on the Withings scale will increase, the lean mass actually goes down. Is this something that I'm doing wrong, or missing, or is this a normal fluctuation? Any of the experts would like to take this question on? I'm sure that over time, I'll reach my goal, I simply would like to understand what's happening, and what I'm doing to my body..
Thanks

oeagleo

I think I found an answer on my own, but for the others who may have the same question, here is a quote from an article posted in another forum:

"Somewhat circumstantially, people using Bioimpedance body fat scales (which use hydration to estimate body fat levels) have noted that body fat appears to go up right before a big drop. This implicates water balance as the issue here. "

The link goes on to explain why weight loss seems to "plateu", and then suddenly "jump".. Very good article to help explain what is actually going on within your body during these times..

http://www.bodyrecomposition.com/fat-loss/of-whooshes-and-squishy-fat.html

:happy:

usmcmp

Try using it when dehydrated then use it again after drinking 32 ounces of water. Your body fat estimation will change dramatically. Calipers and measurements are the way to go instead of the bioimpedance.

nanokoala

The most accurate way to measure BF% is DEXA scan, it is very expensive. And whereas it is the most accurate there is still about 3% of error (meaning if it says 13% BF, you are between 16% and 10%). Bio-impedance is the least accurate.
If you do not have 100€ to spend in DEXA scan, use tape measurement instead of calipers. Calipers are a tidy bit more accurate than tape measurement, but you can't use the calipers yourself and they must be used by a very very very experienced professional (ie : not that guy at the gym).

My advice : use tape measurement with the NAVY bodyfat formula every week, and watch for your mirror (take photos every 2 weeks). You will see improvement. You bodyfat % is not so important, it is how you feel about yourself and your appearance that matters.