Water

Schoie81

http://www.bbc.co.uk/news/magazine-24464774

Interesting read - seems to suggest being dehydrated doesn't affect performance. Basically - if you feel thirsty, drink, if you don't, you're fine.

diamonddog

I have always done this, when I was a half marathon runner I often completed the half without any except on hot days when I would take on a small amount as and when needed. This has carried over to my cycling and still seems to work.

slowbike

So they waited until the subjects were already dehydrated before carrying out the test?
Surely it would've been an idea to have a control exercising on constant hydration and see how the performance is affected in relation to the others.
For a 75Kg person to loose 3% of weight they'd expire 2.25litres of sweat ... that's a lot of sweat! Surely nobody would loose 2.25Litres and then start drinking - they'd be drinking from the get go?

Is it just another flawed experiment?!

Schoie81

the article makes a good point by comparing it to breathing - you can't last long without oxygen, and you use lots whilst exercising, but you wouldn't think i'll breathe faster now because i'm going to be out of breath in 5mins time. Your body feels it needs more oxygen, so it automatically starts your lungs puffing like a steam train, if it needs more water - it makes you feel thirsty. Slightly flawed in that your body hasn't really got anywhere to store oxygen for use later, whereas it can store water, but there is some logic in it...

Also interesting that it claims you CAN count the water in food, tea, coffee and even alcoholic drinks towards the amount of water you're taking into your body - something which I've always been told you can't.

Its how I drink too really. I also do a bit of running, and I don't tend to drink on the run unless i'm doing more than 7 or 8 miles - probably 20-25 miles on the bike, unless its hot...

diamonddog

Every one has different ways of doing things, if I drink a lot of fluids during excercise it tends to give me a bloated feeling.

Schoie81

Slowbike wrote:

For a 75Kg person to loose 3% of weight they'd expire 2.25litres of sweat ... that's a lot of sweat! Surely nobody would loose 2.25Litres and then start drinking - they'd be drinking from the get go?

Is it just another flawed experiment?!

Also a very good point!! Should really have had a 'control' that never got dehydrated in the first place. Maybe they did, but it wasn't mentioned in the BBC article....?

Bozman

I can remember reading an article years ago claiming that athletes performed better closer to dehydration, but I can say that I've never seen anything similar since.
Little and often works for me but I never drink that much on a ride, 750ml every 50 miles in the summer and anywhere between 250 and 500 in the winter.

keef66

Alcohol aside, I only ever drink when I'm thirsty. I never ever believed the oft repeated 'you need to drink at least 2 litres of water a day'. Empirical evidence suggested I was fine on 3 or 4 cups of tea instead.

In winter I can ride for several hours and drink relatively little. Riding in the summer I'm drinking 500mls an hour or more. It's not rocket surgery!

bondurant

One would hope not. Poor old rockets.

simon_e

Bozman wrote:

I can remember reading an article years ago claiming that athletes performed better closer to dehydration, but I can say that I've never seen anything similar since.

I have. Some sports scientists and observers claim that the effect of dehydration on performance has been exaggerated and additional fluid intake promoted heavily by sports drink manufacturers. Not sure where I read it now but possibly the Sweat Science column on Runner's World.

GGBiker

would be interesting to see the effect of dehydration on power output as losing 2.5kg of weight before a long climb could result in an increased climbing speed if power output was not significantly lower.....

Bozman

Simon E wrote:

Bozman wrote:

I can remember reading an article years ago claiming that athletes performed better closer to dehydration, but I can say that I've never seen anything similar since.

I have. Some sports scientists and observers claim that the effect of dehydration on performance has been exaggerated and additional fluid intake promoted heavily by sports drink manufacturers. Not sure where I read it now but possibly the Sweat Science column on Runner's World.

I think that the article was in a running publication, a work mate was a long distance runner and he never took fluid with him on his training runs, the guy used to sweat like a pig too.

tapscrew

If your thirsty drink, and it dosnt really matter what (not booze!) I frequently cycle for over 2 hours and never drink, I also often run for upwards of 2 hours and never drink then either- very uncomfortable to have fluid bouncing around inside! I was once told but some sort of fitness guru that you should be weeing about 15 times a day to ensure your not dehydrated!!!! NUTS- and the 2 liters a day thing is crap also.

mrfpb

There has never been a scientific study that said you must drink two litres of water a day. Lots of people have looked for one, because it's so often stated as fact, but there isn't one on record. It's the health equivalent of an urban myth. Studies on fluid intake say that all water - whether in soft drinks, tea, coffee or food count towards your intake of water. On the One Show last year they had a sports nutritionist saying skimmed milk was the best drink for rehydration after exercise - I’m not going to be carrying it on a ride though

Mikey23

Exactly the point that 'trust me I'm a doctor' was making

Another runner here and I didn't do much drinking on runs up to half marathon and then only in hot conditions. I only ever take one bottle on the bike and this will last me up to 4 hours. Tesco apple squash is my current favourite. I never did quite get that sport drink, bottled water, gel thing and always thought it was a big con. But if it works for you then that's ok

kajjal

Dehydration does have an impact as we found when we ran out of water mountain biking on a very hot day but I think it is overstated and different people dehydrate at different rates. After long mountain bike rides in hot weather even when drinking what seems like plenty of water there is still a lot of weight loss which also could counterbalance dehydration effects to some extent.

slowbike

I've read somewhere that just taking a bit of water in your mouth triggers your liver(?) to release/produce stuff that helps your muscles work - or burn fat or something.... (you can tell I'm scientific! )

So perhaps taking on liquids isn't just about hydrating ...

Personally I carry around 100ml or so on an 11 mile commute and not drink all of it - I just use it to wash my mouth when it feels dry. I know I've had enough to drink prior to the ride and will usually have a big drink after the ride. However, on a 30 mile hard ride (after a 40 mile potter) I drank best part of 750ml and needed all I drank as I could feel cramp coming on in my calf muscle.

team47b

Slowbike wrote:

I've read somewhere that just taking a bit of water in your mouth triggers your liver(?) to release/produce stuff that helps your muscles work - or burn fat or something.... (you can tell I'm scientific!

You really should post that over on Training, Fitness and Health section, it would create some real fun :twisted:

plowmar

On a personal level I did, recently, a 50 mile ride that I would normally only need 500ml of drink, this day I took 1 litre of drink and all but collapsed due to lack of water. A couple of pints when I got home put me right.

So on that unscientific exercise dehydration is not the best state in which to exercise.

W12_Lad

I'm interested in this. And any one's constructive thoughts are appreciated.
I drink a lot of water in general.
Judging by the comments, when cycling, it seems I drink a hell of a lot more water than most people on here.
I make sure I'm hydrated pre ride (but estimating not enough to be needing the loo!).
When I do a regular 70 miler (around 4hr 20), I bring a couple of 1 litre bottles on the bike and carry a 700 ml bottle in my jersey. It always gets used. I don't feel dehydrated on that amount but I could probably drink more. I drink more once home.
The next time I go to the toilet after the ride, my wee is always noticeably dark yellow.

team47b

Do you live in the UK?

Do you sweat more than most too?

W12_Lad

I live in London and I do sweat a lot when exercising. Not sure if it's lots more than others though.

diamonddog

W12 lad wrote:

I'm interested in this. And any one's constructive thoughts are appreciated.
I drink a lot of water in general.
Judging by the comments, when cycling, it seems I drink a hell of a lot more water than most people on here.
I make sure I'm hydrated pre ride (but estimating not enough to be needing the loo!).
When I do a regular 70 miler (around 4hr 20), I bring a couple of 1 litre bottles on the bike and carry a 700 ml bottle in my jersey. It always gets used. I don't feel dehydrated on that amount but I could probably drink more. I drink more once home.
The next time I go to the toilet after the ride, my wee is always noticeably dark yellow.

That seems like a big liquid intake over that period even in our hot weather let alone when it's cooler.

diamonddog

The colour of your urine indicates dehydration but as you say you don't feel that way especially with the amount you drink, is it just water you drink on your rides or some type of energy drink mixture if it's the latter that could be the reason for the yellow colour.

W12_Lad

I use High 5 zero tabs.
It didn't occur to me that they may darken my urine.
I use 1.5 tabs per litre, so not very strong.

diamonddog

You could try a ride with just water see what the results are, you can take jelly babies or something else to munch for the energy dips.