Appearently they did a study on how precise it is, "Comparison of Circumference-and Skinfold-Based Body Fat Estimation Equations", where they compared their formula with several other methods for body fat estimation, against a baseline set by hydrostatic weighting. I couldn't find the full text online (at least not for free), but the abstract is here:
Quote: "For men, the Navy equation was the best predictor of body fat determined by hydrostatic weighing."
So all you need to track your body fat is a measuring tape plus a pen and a pad. That's too much of an effort for me, though, so I use one of the web-based calculators, e.g.
%Fat=495/(1.0324-.19077(log(abdomen-neck))+.15456(log(height)))-450
Appearently they did a study on how precise it is, "Comparison of Circumference-and Skinfold-Based Body Fat Estimation Equations", where they compared their formula with several other methods for body fat estimation, against a baseline set by hydrostatic weighting. I couldn't find the full text online (at least not for free), but the abstract is here:
http://stinet.dtic.mil/oai/oai?verb=getRecord&metadataPr...
Quote: "For men, the Navy equation was the best predictor of body fat determined by hydrostatic weighing."
So all you need to track your body fat is a measuring tape plus a pen and a pad. That's too much of an effort for me, though, so I use one of the web-based calculators, e.g.
http://www.dietandfitnesstoday.com/body-fat-percentage-calcu...
(you need to allow JS to use it).