To wear a shirt or not?

To wear a shirt or not?

Post by ken.. » Wed, 29 Jul 1992 05:14:34


To any of you hot weather running knowledge meisters:

Is it better (cooler temperature-wise) to wear one of the high tech fabric
uppers than not to wear any shirt at all while running in the hot & humid
summer weather?  Do these fabrics promote evaporation and cooling better than
plain old exposed skin?

I hate wearing a shirt/singlet on top when the weather gets much above 60 and
it's really humid outside.  A typical 6AM temp. & humidity in Dallas is
77 degrees and 80% humid.  It's not even reasonably feasible to run any other
time, unless you just want to put in a fast mile or less...

Ken Papai

 
 
 

To wear a shirt or not?

Post by Wolfgang Koehl » Wed, 29 Jul 1992 22:10:04

|> To any of you hot weather running knowledge meisters:
|>
|> Is it better (cooler temperature-wise) to wear one of the high tech fabric
|> uppers than not to wear any shirt at all while running in the hot & humid
|> summer weather?  Do these fabrics promote evaporation and cooling better than
|> plain old exposed skin?
|>
|> I hate wearing a shirt/singlet on top when the weather gets much above 60 and
|> it's really humid outside.  A typical 6AM temp. & humidity in Dallas is
|> 77 degrees and 80% humid.  It's not even reasonably feasible to run any other
|> time, unless you just want to put in a fast mile or less...
|>
|> Ken Papai

Unless you are a woman I'd advice to run without anything on top :-).

Seriously, I prefer to run without any shirt when its hot and never had
any problems with that.

No high-tech material can evaporate better than the pure skin.
On the other hand, its quite unpleasant  to run with an wet shirt after
a while.
I`ve realized that this sometimes caused a cold of my kindneys.

wolf

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To wear a shirt or not?

Post by Jim Pucke » Thu, 30 Jul 1992 01:57:55

<stuff deleted>

Quote:
>No high-tech material can evaporate better than the pure skin.

are you sure, wolf? many mornings it seems that my Cool-Max shirt is
dry before my skin.

Quote:
>On the other hand, its quite unpleasant  to run with an wet shirt after
>a while.

that's true - over ten miles, and I need noxema on the nips!

Quote:
>wolf

just one more mile,

jim p.

--

Huntsville,AL (205)461-4922  
This life is a test. It is only a test. If it had been a real life, you
would have been given instructions....

 
 
 

To wear a shirt or not?

Post by David Frankl » Thu, 30 Jul 1992 04:37:24

I have been told by former coaches that running with a shirt on will decrease
the rate of water evaporation from the skin.  This in turn will decrease the
rate of dehydration.  So if you want to run in hot weather without a shirt on,
you probably should be careful to hydrate yourself frequently during the run...

Happy trails,
Dave

---B-O-S-T-O-N---U-N-I-V-E-R-S-I-T-Y-----------------------------------------
-------------------------------C-O-L-L-E-G-E---O-F---E-N-G-I-N-E-E-R-I-N-G---

 
 
 

To wear a shirt or not?

Post by Carl Krasn » Thu, 30 Jul 1992 06:14:11

Quote:

>I have been told by former coaches that running with a shirt on will decrease
>the rate of water evaporation from the skin.  This in turn will decrease the
>rate of dehydration.  So if you want to run in hot weather without a shirt on,
>you probably should be careful to hydrate yourself frequently during the run...

>---B-O-S-T-O-N---U-N-I-V-E-R-S-I-T-Y-----------------------------------------
>-------------------------------C-O-L-L-E-G-E---O-F---E-N-G-I-N-E-E-R-I-N-G---

Wrong! Wrong! Wrong! You oversimplyfy and come to a false conclusion. If you
are correct that a shirt will decrease the rate of evaporation, then wearing
a shirt will INCREASE the rate of dehydration. Your body dehydrates via
perspiring and perspiring is a response to elevated body temperature. The
reduced evaporation rate you refer to reduces the rate of cooling and the
body will compensate by sweating MORE. Your body has no sensors to check that
the skin is already wet.

To convince you further, another factor which decreases evaporation rate is
increased humidity. No one would try to argue that elevated humidity levels
reduce your rate of dehydration during a run. (However this may be true for
a lettuce in the fridge!).

To take your logic to its absurd conclusion, if one were to wear a snug
body suit made out of******, one should be able to cover enormous
distances without water.

To summarize, in the heat, runners should do everything possible to
FACILITATE evaporation of perspiration from the skin and this will
MINIMIZE the rate of dehydration!!!!!

--
===============================================================================
Carl Krasnor, Communications Research Lab, McMaster U., Hamilton, Ont. CANADA

===============================================================================

 
 
 

To wear a shirt or not?

Post by Preston Brig » Thu, 30 Jul 1992 05:46:13

Quote:

>To summarize, in the heat, runners should do everything possible to
>FACILITATE evaporation of perspiration from the skin and this will
>MINIMIZE the rate of dehydration!!!!!

To simplify, say that runners should do everything possible to
facilitate evaporation of perspiration, thus achieving best cooling.

As an orthogonal issue, runners should also be sure to drink enough
fluids.

Preston Briggs

 
 
 

To wear a shirt or not?

Post by Ashish Mukhar » Thu, 30 Jul 1992 08:18:44

Quote:


>>To summarize, in the heat, runners should do everything possible to
>>FACILITATE evaporation of perspiration from the skin and this will
>>MINIMIZE the rate of dehydration!!!!!

>To simplify, say that runners should do everything possible to
>facilitate evaporation of perspiration, thus achieving best cooling.

>As an orthogonal issue, runners should also be sure to drink enough
>fluids.

Well, then why is it that competitive runners always seem to wear
singlets when racing?  All I can come up with is they don't want to pin
the number to their bare skin.  :)  There must be a better reason.  More
room for ad space?  It's not only top runners who do this ...  running
sans shirt seems so much more comfortable to me.

Quote:
>Preston Briggs

-ashish

--
Ashish Mukharji       Jesus he knows me, and he knows I'm right,

 
 
 

To wear a shirt or not?

Post by Ward_Tra.. » Thu, 30 Jul 1992 05:28:24

I've found that I prefer wearing no shirt over wearing any COTTON
shirt. I perspire heavily, and after about 5-7 mi. a cotton shirt will
be soaked. If the shirt gets heavy enough, it will chaff my chest
right across the most sensitive parts (yep, there). The chaffing has
inconvenienced me for a couple of days after some of my longer runs.
So for me, it's no shirt unless it's too cold to not wear one. And
then, I try to get something non-absorptive on as a first layer.

--
Ward C. Travis          Pittsburgh PA   "The fact is the sweetest dream that

 
 
 

To wear a shirt or not?

Post by Francesco La » Thu, 30 Jul 1992 08:30:20

I think that a shirt, expecially a white one, is very useful if it's sunny,
because it reflects the sun's rays.
Direct irradiation from the sun is a big factor in body overheating, as you
can figure well when you get into the shadow.

                     FRANCESCO

 
 
 

To wear a shirt or not?

Post by Martin Strau » Thu, 30 Jul 1992 10:51:46

You can't perspire (well) through sunburnt skin.  Even a singlet gives
some protection, as evidenced by tan lines (disclaimer: use sunscreen
for more protection).

A singlet will keep the moisture on your skin, so it will evaporate
taking some heat with it, rather than drip off or get blown off in the
wind.

Martin

 
 
 

To wear a shirt or not?

Post by Michael Bra » Thu, 30 Jul 1992 22:34:25


|>
|> I think that a shirt, expecially a white one, is very useful if it's sunny,
|> because it reflects the sun's rays.
|> Direct irradiation from the sun is a big factor in body overheating, as you
|> can figure well when you get into the shadow.
|>
|>                FRANCESCO

Finally, someone brings up this point. However, there is a trade-off here,
being that the gain in reflecting away the sun's rays is offset by the
reduction in the evaporation rate, particularly when the humidity is
relatively high. If the conditions are dry, there is probably some benefit
to wearing a shirt, if it is quite light, and preferably quick drying...

Noticed in another post a question about top runners, and others wearing
singlets in races...most track meets run by any of the major governing
bodies have uniform requirements (not going to argue the logic of these
rules), so the athletes are probably just sticking to habit in road races.
Sponsorship is of course a major factor, as is fashion. Some of us may be
trying to hide the skeletal physique we have worked so hard to attain :-)

Michael Brady ------------------------------------------  __o

Boston University Physics ------------------------------  /-
------------------------------------------------------   / '

 
 
 

To wear a shirt or not?

Post by Robert W. Bra » Fri, 31 Jul 1992 02:40:46

Quote:

>Well, then why is it that competitive runners always seem to wear
>singlets when racing?  All I can come up with is they don't want to pin
>the number to their bare skin.  :)

Race belts solve this problem.  I don't like the pin holes
in singlets when I wear them either.

Quote:
>There must be a better reason.  More room for ad space?  

bingo.  That and probably 'tradition' like wearing white at Wimbledon.

Quote:
>It's not only top runners who do this ...  running
>sans shirt seems so much more comfortable to me.

Top triathletes often run sans shirt (and sans socks, pants,
and anything else they can legally take off).

Quote:
>>Preston Briggs

>-ashish

>--
>Ashish Mukharji       Jesus he knows me, and he knows I'm right,


--
Bob Brand