You're right to be bothered about body fat measurements rather than just your weight.
Knowing what percentage of your body weight is fat and what is lean tissue is far more reliable indicator of how your workout is going than just standing on your scales in the bathroom.
Actually measuring body fat percentage is the hard part! There's three ways:
Skinfold calipers
The cheapest way to measure body fat as all you need is a pair of calipers, either manual or digital.
Some gyms will have calipers and will do all the measurements for you, so ask at yours.
If you'd sooner track your body fat in the privacy of your own home, you can pick up a pair for under £20. Mansized recommends Accumeasure skinfold callipers.
For full instructions on how to use them click here.
Bioelectrical Impedance
You're sure to have seen body fat scales made by companies such as Tanita and the like.
They can give you a rough idea of your body fat, but the kit's more expensive than calipers and more prone to error.
The most common devices work by either standing on a set of scales which have metal electrodes built in, or using a hand held device which has the electrodes built into the handles.
The device then passes a very low electrical current through the body, estimating body fat levels by comparing the resistance of your body with your height and weight.
The theory's pretty straightforward. The electric current has a harder job getting through fat than muscle, so the gadget can work out how much fat you have.
There's one problem though - the measurement depends on how much water is in your body at the time. Take two readings, one after drinking a glass of water, and there's every chance you'll get two different numbers!
Most gyms will stock these gizmos, but there's little difference between these and the kind you can buy off the shelf. Theirs may have more decimal places and a button to press to print the reading out, but the pro kit generally isn't any more accurate.
If your gym offers body fat measurement, you're better off insisting that one of their qualified professionals use skinfold calipers.
If you still want to buy the kit, try Tanita's Active Body Composition Scales at a more prohibitive £50.
To get the most from your scales, try these tips.
Hydrodensitometry
By far the most accurate method of measuring body fat and used by most professional athletes.
Simply immerse yourself fully in water and the amount of water displaced indicates how much body fat you have.
It won't work in your bath though! You need professional kit, access to a university physiology lab and a trained technician. None of which Mansized has kicking about.
