Bodyfat machines.

[Jamie Taylor]

Can someone explain to me how these fancy bodyfat machines work, and why if you say you are athletic rather than normal it takes about 7% bf off what your % would be if you had inputted normal.

Surely it reads how much fat you have, how can pressing a different key give a completely different bf reading ?

[droc]

They don't, really.

As someone on here has already said (boxingbrit I think) the only real use they have is showing that you are consistently losing bodyfat, but they're not accurate.

DROC

[Sports-Select.co.uk]

Can someone explain to me how these fancy bodyfat machines work, and why if you say you are athletic rather than normal it takes about 7% bf off what your % would be if you had inputted normal.

Surely it reads how much fat you have, how can pressing a different key give a completely different bf reading ?

They use a mix of electrical impedence, the data you entered and basic BMI calculations so they are not accurate by any means. Because an athlet has A)more muscle and B)different muscle composition to a non trained individual it needs to know this to try and factor it into its calculations.

Multi site skin calipers testing is probaly more accurate if done properly.

[Cheets]

These machines aim to estimate body density which is then re-calculated into a bodyfat% the orginal equations devised (and still used by the machines) were done using very limited selection white european males (and females - seperate calculation). There are lots of equations in existence for lots of different populations - these machines only have a couple or so at best.

In leaner people - body density distributions/proportions change slightly therefore a different calcuation is used by the machine. The machine itslef is considered very inaccurate and only reliable/consistent when strict pre-test guidleines are adhered to - my advice (well ,not just me, every anthropometrist) is find someone who is trained to use the skinfold method - this is way more accurate when the same person is doing the measures - my final advice is not to use the bodyfat calculation as this is actually the largest source of error - just record the skinfold thickness and monitor the change.

[Cheets]

sorry - computer playing up

[West Fight Company]

i have one and use it when trying to lose or maintain bodyfat as a general guide - if the percentage is going down or not increasing - winner.

But its not accurate as the results vary when done within seconds of each other.

[Jamie Taylor]

Thanks guys. I had the test done today with the calipers and turned out the same :( lol.

A few people have said the 3 site caliper tests are inaccurate as well so I reckon I'm not as fat as theyre making out.

[stapesmk1]

Try find a local uni or training centre with a bodpod machine. Loughborough and leeds met have them.

Stapes