1.5 litres of sweat

[lulubel]

Out of curiosity, because I'd been in a discussion on another forum about how much or little different people sweat, I weighed myself before and after my ride yesterday. I was on the bike for 2 hours 20 minutes, drank a litre of water during that time (so roughly 2lb in weight), but weighed 1lb lighter when I got home.

I make that 3lb lost in sweat, which in volume terms is about 1.5 litres.

I was quite shocked. It isn't cold here by UK standards, but I was feeling a bit chilly at the start of my ride, before I got warmed up. It makes me wonder what my fluid loss is like in the summer when it's hot.

 

[numbnuts]

During hot summer days (when did we have the last one) I can weight 3 kg lighter after a long ride

 

[tadpole]

I can an do lose 2- 4 lb in two hours ride or a 50 minute run. I weighed myself before and after a ride/run. And that is with drinking 2 pints of water.

 

[GrumpyGregry]

0.75 to 1.5 litres fluid loss per hour is the "normal range" iirc.

But it isn't all lost as sweat, just breathing hard loses a fair bit.

And I think I remember reading somewhere that in extreme conditions sweat rates can be higher when you're not exercising as the muscles aren't competing with the skin for fluid.

 

[Becs]

As Greg says, a lot of that will be water vapor in your breath

 

[ColinJ]

6-7 litres of fluid losses on one 6.5 hour summer ride. (Based on an assumed 0.5 kg fat burn, the drop in my weight and what I ate and drank on the ride.) So that is about 1 litre per hour on a hilly ride on a hot day.

 

[MattHB]

I sweat quite a bit too as I tend to run fairly hot. A winter 4 hour ride and ill still loose about 1.5 kg.

Question though, how much does the glycogen weigh that you burn off in that time? Sugar is heavy stuff so it must have an impact surely?

 

[lulubel]

Question though, how much does the glycogen weigh that you burn off in that time? Sugar is heavy stuff so it must have an impact surely?

I ate a piece of cake part way through my ride, so that definitely replaced some of it.