Sweating, thermal efficiency, and other pointless ruminations



Hi All,

Yesterday I had a pleasant evening watching 2006 TdF stage 17 on DVD
while riding my rollers out in my shed. At one point my wife came out
to see if I had crashed or something (stage 17 was long!) and she
commented how hot it had become out in the shed.

Considering it is a non-insulated shed, and the outside ambient temp
was around 4C, this was surprising.

I estimate I had an average power output of about 200-250W. So this
means I was actually heating up the room with 800-1000W total for
several hours, correct?

But I have a theory, based on the fact that I do not sweat that much.
My theory is that I have a somewhat higher than average thermal
efficiency while cycling. Is that possible, and if so would sweat
quantity be any indication of such a thing? At my size, my volume to
surface area should be working against me as far as keeping cool, but
I don't seem to have any problems.

But then again, I don't have any problems staying warm either. I don't
need anything other than normal cycling shoes and paper thin socks
until it gets below freezing, and only then if I plan to be out for a
while.

So is it possible I have high thermal efficiency? If I do, does it
have any practical impilcations?

Joseph
 
B

Ben C

Guest
On 2007-04-17, [email protected] <[email protected]> wrote:
> Hi All,
>
> Yesterday I had a pleasant evening watching 2006 TdF stage 17 on DVD
> while riding my rollers out in my shed. At one point my wife came out
> to see if I had crashed or something (stage 17 was long!) and she
> commented how hot it had become out in the shed.
>
> Considering it is a non-insulated shed, and the outside ambient temp
> was around 4C, this was surprising.
>
> I estimate I had an average power output of about 200-250W. So this
> means I was actually heating up the room with 800-1000W total for
> several hours, correct?


That sounds about right as 25% is the figure usually used for the
efficiency of a rider.

> But I have a theory, based on the fact that I do not sweat that much.


How can you tell though? It might just be that conditions in your
shed/environment are low in humidity so the sweat evaporates quickly.

> My theory is that I have a somewhat higher than average thermal
> efficiency while cycling. Is that possible, and if so would sweat
> quantity be any indication of such a thing?


I suppose so but difficult to measure. Perhaps a better test would be
underwater cycling (on some kind of stationary bicycle probably). The
water would be in a well-insulated container, and you would measure the
temperature rise in the water after several hours of "riding".
 
On Apr 17, 8:08 pm, Ben C <[email protected]> wrote:
> On 2007-04-17, [email protected] <[email protected]> wrote:
>
> > Hi All,

>
> > Yesterday I had a pleasant evening watching 2006 TdF stage 17 on DVD
> > while riding my rollers out in my shed. At one point my wife came out
> > to see if I had crashed or something (stage 17 was long!) and she
> > commented how hot it had become out in the shed.

>
> > Considering it is a non-insulated shed, and the outside ambient temp
> > was around 4C, this was surprising.

>
> > I estimate I had an average power output of about 200-250W. So this
> > means I was actually heating up the room with 800-1000W total for
> > several hours, correct?

>
> That sounds about right as 25% is the figure usually used for the
> efficiency of a rider.
>
> > But I have a theory, based on the fact that I do not sweat that much.

>
> How can you tell though? It might just be that conditions in your
> shed/environment are low in humidity so the sweat evaporates quickly.


I wasn't thinking in particular about out in the shed. I was making an
entirely subjective guess based on my observations of other riders out
on the road, and in spinning sessions. And based on my comparative
water intake on long rides.

>
> > My theory is that I have a somewhat higher than average thermal
> > efficiency while cycling. Is that possible, and if so would sweat
> > quantity be any indication of such a thing?

>
> I suppose so but difficult to measure. Perhaps a better test would be
> underwater cycling (on some kind of stationary bicycle probably). The
> water would be in a well-insulated container, and you would measure the
> temperature rise in the water after several hours of "riding".


Thermal efficiency I beilve can be calculated by measuring the volume
and consistency gases in the air breathed during exercise.

But suppose the thermal efficeincy were "better" or whatever word one
would qualify it as, what would that mean in terms of what happens in
the real world?

Joseph
 
F

Frank Miles

Guest
In article <[email protected]>,
[email protected] <[email protected]> wrote:
>Hi All,
>
>Yesterday I had a pleasant evening watching 2006 TdF stage 17 on DVD
>while riding my rollers out in my shed. At one point my wife came out
>to see if I had crashed or something (stage 17 was long!) and she
>commented how hot it had become out in the shed.
>
>Considering it is a non-insulated shed, and the outside ambient temp
>was around 4C, this was surprising.
>
>I estimate I had an average power output of about 200-250W. So this
>means I was actually heating up the room with 800-1000W total for
>several hours, correct?
>
>But I have a theory, based on the fact that I do not sweat that much.
>My theory is that I have a somewhat higher than average thermal
>efficiency while cycling. Is that possible, and if so would sweat
>quantity be any indication of such a thing? At my size, my volume to
>surface area should be working against me as far as keeping cool, but
>I don't seem to have any problems.
>
>But then again, I don't have any problems staying warm either. I don't
>need anything other than normal cycling shoes and paper thin socks
>until it gets below freezing, and only then if I plan to be out for a
>while.
>
>So is it possible I have high thermal efficiency? If I do, does it
>have any practical impilcations?


Biochemistry is pretty consistent across our species. And for a long
period, heat storage or transfer rapidity won't be an issue. What might
be related is how efficiently you work. That is, keeping muscles loose
that shouldn't be working. Perhaps decreasing other non-work loads,
like GI tract, kidneys, brain,... :)

My guess is you're probably not that different. Weather, clothing, and
training are more likely reasons.

-f

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