How accurate is Boditrax at measuring bf%?

The technology used is bioelectrical impedance. It can be widely inaccurate and highly affected by hydration.

One test isn’t going to tell you much. Take the test numerous times over the course of a week ensuring you are properly hydrated each time and take it at the same time of day under the same circumstances.

Alan

Tape circumference is also a horribly inaccurate method.

My guess is that if you’re more or less “athletic” and have been “athletic” for a number of years then your body fat is between 14-20%. On the lower end if you’ve been a competitive runner for a while. Much under 14%, closing in in 10%, you would likely experience amenorrhea, which is common in lean female athletes.

Alan

My weight has been up and down over the years, I have never been competitive or particularly fast, I am injury prone (always have been) so my mileage has not been super consistant, maybe ranging between 10 and 40 mile weeks over the last 2 years. My 5k shape hovers around 21-23 just to give you an idea of my fitness level, maybe that sort of time would indicate around a 20% body fat level but ceertainly not an elite marathonner sort of level

On top of running I also swim. I do get told I am very thin quite regularly and although I have solid muscle underneath I do actually have a bit of a gelly pooch, I am fairly defined in my legs and arms but again, not SUPER defined. I hope my body fat is closer to 12%, I don’t want to look worryingly unhealthy.

Jen Dash wrote:

gelly pooch

Belly pooch* that was supposed to say

I wouldn’t worry about it. Just train and eat healthy. Body fat is just a number.

You can look up pictures of what various body fat levels “look” like. You can also look up YouTube videos basically debunking this. Someone with crazy vascularity and super abs but DEXA scan showing like 15% bodyfat on a male.

It doesn’t really matter.

Alan

BMI is a calculation based on height and weight---pretty hard to screw that up.

BIA can be affected by a few things so it is best to look at the manufacturer's recommendations for testing. Typically they will say to be properly hydrated and will tell you not to be tested within some time period after eating or exercising.

The closer you follow the instructions the more reliable and valid the measurement will be.

BIA under good testing procedures are still +/- 3 percentage points so that 12% could be somewhere between 9 and 15% in reality.

Measure before and after you workout . Loss of body water effects my readings.

@runningart2004 The main reason I feel the need to know if it is because I do not want to stop mestruating or be unhealthy, not because I am concerned about hitting numbers that don’t really matter. I am smart enough to know that a 20% body fat woman can perform better than a 15% body fat woman if they have a higher level of conditioning, plus evryone is different and some people may run better and be a lot healthier at a higher body fat.