As noted, they are good for relative measurements, but not accuracy of bf. If you get a better test, immersion, good caliper test, etc., and use the Tanita, you can kinda track where you are.

Tanita has a new scale that was just discussed on Velonews or some place. $300, but it has retractable hand grips for measuring internal composition of soft tissue in all areas of your body (arms, torso, legs, etc.). It's the cheap version of one of the pro models like this one: http://www.healthchecksystems.com/pr...product_id=987

Brown fat good, yellow fat bad.