UKC

Hi all,

Maybe a naive question but;

Does your heart rate increase the more you sweat?

E.g. If I run outdoors for 10km with just a tee-shirt on will my heart rate be lower than if I ran under the same conditions with a tee-shirt, long sleeved tee-shirt and a jacket?

Cheers
Giles

In reply to Giles Davis:

I might be about to be proved wrong here, but as far as I know it doesn't. I've known lots of people who've gone to various lengths to sweat more during exercise. making arm and head holes in a bin liner and wearing it under three sweatshirts for instance - some anti-social types used to do squats in the sauna similarly attired. Anyway, the PTI staff used to regularly advise us not to. The reason being that all it does is dehydrate you faster. True you'll finish your workout lighter, but you'll put it straight back on as soon as you take a drink.

In reply to Giles Davis:

I'm sure a pe scientist will be along soon to give the definitive answer.

Until then, I think that sweating increases heart rate as it reduces blood volume so the heart had to beat faster to maintain perfusion.

In reply to Giles Davis:

That's an interesting question and my main thought is 'why do you want to know?'. I guess that heart rate will increase with sweat rate as it has to work harder, but I've just searched some journals and there is no paper that I have found that specifically discusses this.

However, as alluded to above, exercising hard while wearing too much clothing is a bad idea and will stress the body in the 'wrong' way. Sweating profusely is not necessarily the sign of a 'good workout' and is a sign that the body is desperately trying to maintain thermogenesis. If cooling is ineffective then you can cause yourself more harm than good.

In reply to Giles Davis:

Id say yes due to the body having to work harder to cool you with all the extra layers.

In reply to Run_Ross_Run:


It's not as though your metabolism powers a cooling system though. Heat loss is achieved by capillary dilation and sweat evaporation. layering up will interfere with this, but I can't imagine your heart rate going up to compensate. I may be wrong, I'm neither a PTI nor a medic.

In reply to Mr Fuller:

Thanks for all the answers guys;

Mr Fuller;

I wanted to know as I have a 7km circuit around my town that I run a few times per week and according to my Garmin Watch / HRM my calorific loss differs by 50 calories or so even when I've run it about the same pace. In the winter I normally run with a base layer tee, long sleeved second base layer / running shirt and a light weight water proof jacket (sometimes to keep the wind off and sometimes to keep the rain off).

So, if sweating more increased my heart rate and took me out of the main calorific burning zone (which I believe to be around 2.8 - 3.1) then I would maybe ditch the jacket on calm / mild nights.

Run Ross Run;

That's what I was thinking.

In reply to Giles Davis:

!! Ignore it! Look at what it reckons you've done in ascent to see how GPS can be very wrong. Calorie calculations are made by simple formulae in the device to produce, well, some sort of a figure. It bears little relation to reality, where differences in weight, temperature, effort, shoes and all sorts of variables contribute to actual calorie loss. 50 calories is nothing anyway. Why would 50 calories here or there bother you?

Wear clothing that's comfortable to run in.

In reply to digby:
Yep, I thought as soon as I'd mentioned 50 calories it wouldn't make that much difference but I was still curious anyway to find out whether increased sweating led to increased heart rate.

Still, 7km tomorrow

and yes, even though my town is pretty much pancake flat both my phone App and Garmin seem to think I run up and down hills for most of the way!

In reply to Giles Davis:I think you'll find increased body temperature has an effect on heart rate - I guess it depends on the weather and temperature but if you can get yourself uncomfortably hot then you might see see some unusual numbers.

Certainly people with heat dehydration have very high numbers, but I doubt we're going to that extreme here.