Why so many toilet breaks in cold weather?

ThePiedPiper

I've found over the past few weeks that when it's been very cold, say freezing or below it, that I'm taking a lot of pit stops in the first few miles of my long runs. Is this normal? Does your blood thicken as a defense against extreme cold causing bladder to fill up quickly? I'm usually fairly good at judging my hydration levels but have had to stop up to 4 times for toilet breaks on my long runs over the past couple of months.

Mods, my apologies if this is veering on a medical question but I don't seem to be having any kidney troubles at any stage so I'm fairly sure I've no medical issue.

Thanks to anyone who can give me any answer on this.

RayCun

I believe
<ie, what follows is something I read somewhere, sometime, and I have no idea if its true>
that you are more likely to empty your bladder when it is cold because your body is trying to maintain a normal internal temperature, all the working bits in your body are working away, generating heat, but the liquid in your bladder is just sitting there, absorbing heat. Emptying your bladder makes your body more efficient at maintaining the right temperature.
<we now return you to your regularly scheduled, highly informed boards commentary>

mcdonrob

Could it be the fluids you normally lose through sweat (in warmer weather) is now passing through to your bladder, as your body does not need to sweat to cool it down?

G-Money

Has your diet or fluid intake changed recently?

A few months back I started taking on more fluids and eating more fruit. One particular day I'd drank two big glasses of fruit smoothie as well as a cranberry tea, normal tea and quite a bit of water. I was peeing every 20 to 30 minutes for the rest of the day. Thought there was something seriously wrong with me for a while but it all went back to normal the next day.

ThePiedPiper

I'd say it's a combination of the things RayCun and Mcdonrob said. My diet hasn't changed at all. It seems to be just on the long runs on the coldest days that I'm constantly stopping. Lastnight took the p!$$ altogether for want of a better expression on a 15 miler. I'd very little to drink all day, did not bring a drink with me on the run, yet still had to stop 3 times on the first 7 miles. Never seems to be a problem on my shorter faster runs for some reason.

sconhome

Sounds like you're marking a territory.

MrCreosote

Not sure it's completely understood really. It definitely happens to me too. Same thing but worse with going surfing or diving in cold water too- even if I drink nothing and empty straight before getting in the water, I'm guaranteed a massive piss just after coming out (or sometimes before)

2 theories:

1: when it's cold you sweat less so the body offloads the water another way- through the kidneys
2: when it's cold your body shuts down blood flow to the skin. This causes BP to tend to rise, and to prevent this the body pushes extra fluid out through the kidneys. So you pee more.

I prefer theory 2 myself.

KentuckyPete

Yeah, the bladder is definitely more active in cold weather - but I don't think it's running-related - it occurs in other cold situations too.

I worked in a few meat factories for three years doing the onsite IT support. I used to hate doing terminal installs / rewiring / soldering / configuring in the big freezer chills 'cos even with the full insulation gear on I'd still have to tear out for a whizz every fifteen or twenty minutes...