Percent body fat!

I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat. I was then quite surprised that
the results were higher than I expected.

I am a 36 yr old male height 183 cm, weight 63 kg (BMI of about 19). I
cycle approx. 50 hilly miles per day (5 days a week). So although I don't
do much upper body exercise I certainly don't have any excess fat. However,
according to the scales my body fat is nearly 17%. Certainingly in the
normal range but much higher than I was expecting! I had a go with some of
the on-line calculators using height, weight, waist and obtained values
from -2% (?) to 10%. The 10% mark is roughly what I was expecting.

My diet is probably not as good as it could be. To be honest I have enough
difficulty taking in sufficient calories for my daily ride. So maybe diet
accounts for some of it. However, I was wondering what other cyclists
experience of these sort of devices are and what else affects the results on
these machines?

Thanks,

Gordon

thelonghouse wrote:
I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat.

I am intrigued as to how it does that without making some rather
sweeping assumptions, and I think it's entirely likely that the sweeping
assumptions it's making don't really work for you or your body.

I would be inclined to disbelieve the scales and listen to (and look at)
your body directly.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

Peter Clinch writes:

thelonghouse wrote:
I have recently acquired one of new fangled sets of weighing scales
that measures, amongst other things, body fat.

I am intrigued as to how it does that without making some rather
sweeping assumptions, and I think it's entirely likely that the
sweeping assumptions it's making don't really work for you or your
body.

I think they work by passing electric current through your body and
doing some sums based to the resistance, since fat, muscle, bone etc
have different resistances.

No idea what the accuracy of these gizmos tends to be.


I would be inclined to disbelieve the scales and listen to (and look
at) your body directly.


OTOH it could be that the scales are right but there's actually no
problem - 17% is in the normal range... and we we all need a
reasonable amount of body fat to be healthy.

thelonghouse wrote:
I have recently acquired one of new fangled sets of weighing scales that
measures, amongst other things, body fat. I was then quite surprised that
the results were higher than I expected.

I am a 36 yr old male height 183 cm, weight 63 kg (BMI of about 19). I
cycle approx. 50 hilly miles per day (5 days a week). So although I don't
do much upper body exercise I certainly don't have any excess fat. However,
according to the scales my body fat is nearly 17%. Certainingly in the
normal range but much higher than I was expecting! I had a go with some of
the on-line calculators using height, weight, waist and obtained values
from -2% (?) to 10%. The 10% mark is roughly what I was expecting.

-2 is funny.


My diet is probably not as good as it could be. To be honest I have enough
difficulty taking in sufficient calories for my daily ride. So maybe diet
accounts for some of it. However, I was wondering what other cyclists
experience of these sort of devices are and what else affects the results on
these machines?

http://calorielab.com/news/2005/10/2...in-a-nutshell/

BugBear

Paul Rudin wrote:
I think they work by passing electric current through your body and
doing some sums based to the resistance, since fat, muscle, bone etc
have different resistances.

Essentially, yes - muscle holds water, fat doesn't, so as far as I
understand it they work out what your muscle mass is based on your
conductivity, guess your bone etc mass based on lookup tables (this is
why you tell them your height, weight, sex, etc) and anything else is fat.

I find mine quite entertaining, but on a day-to-day basis it tells me
more about how hydrated I am than how much flab I'm carrying.
Yesterday I was allegedly 18% fat (and I wasn't even hungover, dunno how
it got that number), today it's down to 13%. That's actually a pretty
extreme example - usually it changes more gradually than that - but it
gives you an idea.


-dan

--
http://www.coruskate.net/

On Feb 27, 9:42 am, Paul Rudin wrote:
Peter Clinch writes:
thelonghouse wrote:
I have recently acquired one of new fangled sets of weighing scales
that measures, amongst other things, body fat.

I am intrigued as to how it does that without making some rather
sweeping assumptions, and I think it's entirely likely that the
sweeping assumptions it's making don't really work for you or your
body.

I think they work by passing electric current through your body and
doing some sums based to the resistance, since fat, muscle, bone etc
have different resistances.

No idea what the accuracy of these gizmos tends to be.


Most just send the (very small) current up one leg, and down the
other. Cheaper ones assume that you are of average leg length, more
expensive ones allow you to enter your height and/or inside leg length
and asjust as appropriate.
Your sex also affects how fat is distributed around you body, i.e. (in
a generalisation that could get me shot) men with beer guts, women
with large thighs/backside. Again, some will allow you to specify
your sex, other assume an androgynous "average" figure.



I would be inclined to disbelieve the scales and listen to (and look
at) your body directly.

OTOH it could be that the scales are right but there's actually no
problem - 17% is in the normal range... and we we all need a
reasonable amount of body fat to be healthy.

I'd take the measurement at the same time each day for say 10 days or
so, and see how consistent it is. If it's fairly consistent, you
could then see if it drops through the season as you lose body fat.

If it gives consistent readings, and changes in line with what you see
in the mirror, you could take it as indicating "better" or "worse",
but I wouldn't attach too much weight to the absolute number it
produces.

There again, you could just look in the mirror.

hth,

bookieb

Daniel Barlow wrote:

That's actually a pretty
extreme example - usually it changes more gradually than that - but it
gives you an idea.

.... that they're not much use! ;-/

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

On Feb 27, 9:25 am, "thelonghouse"
wrote:
However, I was wondering what other cyclists
experience of these sort of devices are and what else affects the results on
these machines?


My missus got a set of the Tanita(?) scales.....because she thinks we
have more money than sense. They have electrode plates that you stand
on and you input your age, sex and height.

They do tend to be fairly consisent within a range of 13-17% for me
(which varies with the time of year, Christmas being strangely high on
the scale). As mentioned by someone else, my hydration level can
affect the reading by a few percent.

By way of comparison, last year I underwent some physiology tests at
Brunel University as part of some research for a friend of a friend.
This included BMI and percentage fat measurement using scales and
calipers applied to my (not too generous) love handles. Their result
was about 12% so maybe the scales are not too far out. But still a
waste of money ;-)

Daniel Barlow wrote:

Yesterday I was allegedly 18% fat (and I wasn't even hungover, dunno how
it got that number)

Confused? Kebab/curry effects?

On Feb 27, 11:35 am, stevo wrote:
Daniel Barlow wrote:
Yesterday I was allegedly 18% fat (and I wasn't even hungover, dunno how
it got that number)

Confused? Kebab/curry effects?

No - getting lashed the night before will leave you dehydrated the
following day which confuses the resistance reading through the
electrodes!