I’ve got this weird drinking thing. Is it just me?

Okay, this might be a bit weird but I’d love to know the science behind it.

Like most people I know how much water I should be drinking, but chugging it down in sufficient quantities is just a chore and I don’t really drink that much plain water during my day. But as soon as I hop on the trainer, I find it really easy to finish a 600ml bottle (usually with SIs electrolytes) within the first ten mins or so. In fact, I often plan an extra bottle for the start of the ride and I’ve gone as far as extending the warm up by 10 mins just to sit at about 35% FTP and take down some fluid before pressing on with my workout.

So, what gives? Why is it that my body just seems to find drinking fluid so much easier when I’m doing some light work? Is there a change in physiology which enables me to uptake water and electrolytes more easily? I’m starting to wonder if I need to sit on the turbo just to get properly hydrated! @chad I’d love it if you could turn your powers of investigation to this!


I, too, have this weird drinking thing …

EDIT: In all seriousness, just listen to your body. If you don’t feel the need to drink off the trainer, but do when you start even light exercise, just follow its lead.


Do they?

Most people I know believe the myth of 8 glasses of water per day.

It’s totally normal for your body to react to unusual exertion with thirst. I lose huge amounts of water when I train. But for some reason I don’t feel the thirst until some time after the session, then I’m desperate for water all night.

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I had the opposite last week. Went to a training camp; didn’t drink much as it’s quite cold still and I wasn’t thirsty at all; came back heavier despite eating sensibly and smart scales tell me I gained 3kg of water weight. So I’m wondering if my body was retaining water because I didn’t drink enough or if it’s some other muscle / glycogen dynamic at play given a massive increase in TSS and associated shock to the system. Either way it was kinda disappointing to ride 600km and see my weight go up!

This is probably because you’re dehydrated from not drinking enough water throughout the rest of the day. So as soon as you start working your thirst kicks in and you realize your dehydration. If you have trouble drinking water throughout the day, try adding some flavor to it.

If you enter a long workout, ride or race dehydrated, you will struggle to re-capture it on the bike. The body at most and in extreme conditions can absorb 1 L of fluid per hour. So if you start off dehydrated and your sweat rate exceeds your body‘s ability to intake and process fluid/water, your performance will suffer because of ever increasing dehydration.

Weigh yourself before and after a ride and see what percentage of body weight you are losing. This will give an idea of your hydration levels. Performance is increasingly diminished as you lose a percentage of your weight. At a 4% loss your performance is cut by 20 to 30%. Conversely, if you have gained weight then you were drinking too much.


IMO, one has train your body to drink more water. Keep that radiator topped off. For me it is to drink before I am thirsty. If I have an evening ride / workout / race, I start pounding water early. Additionally, it is an everyday thing, not just I have to ride tonight better get hydrated. If I am not properly hydrated I do drink more during an effort.

Edit: Plus 1 to the above. @MI-XC

What’s wrong with this? Sounds like a good guide to me :thinking:

I am on the bike training at 4:30 x 4 days and do strength training at 5:30 x 2 days. Before each type of workout, I try to consume at least 32-40 ounces of water to make up for overnight dehydration, and on the bike I drink at least the same amount. Pretty much the same on strength training days. Overall, I shoot for 3 to 4 gallons of water a day. The body needs a ton of water to keep healthy and well-hydrated.

It turns out to be totally unsupported by any sort of evidence: "The likely origin of the oft-quoted advice may be a 1945 publication from the National Research Council’s Food and Nutrition Board that stated that an “ordinary standard” of water for adults is 1 mL for each calorie of food. So, a person who eats 2,000 calories per day would require 2,000 mL of water, or roughly 8 cups.

" However, the subsequent sentence by the Food and Nutrition Board—“Most of this quantity is contained in prepared foods”—may have been ignored, and so this recommendation was likely misinterpreted as an instruction to drink 8 glasses of water each day."

No study has ever backed up that you need to actually drink 8 glasses of water a day. The current medical advice is “drink when you’re thirsty”


I cannot remember what this is called but having your thirst triggered during the first 10-20 minutes of a workout is pretty common. I remember it being mentioned in the FLO Cycling podcast… one of the first 1/2 dozen episodes IIRC.

I experience the same thing at the gym and on the trainer but I don’t experience it when I’m out in the real world (hiking, riding, etc). FWIW, I think I’m well hydrated most of the time and the sudden onset makes me believe that the rise in stress or other science stuff triggers a really basic desire in our chimp brains.

There is an interesting article on FiveThirtyEight from last week on the lack of good science in this field: https://fivethirtyeight.com/features/you-dont-need-sports-drinks-to-stay-hydrated/


It’s a fantasy. It’s made up. There was, and is, no science behind it. Someone said it once and everyone just believed it. :slightly_smiling_face:

Have a look at Tim Noakes work, I’m sure Chad has referred to it in the podcasts a few times. :+1:

If I actually followed that I would be seriously under hydrated. I’ve never often felt the need/urge to drink, I have to make myself. And when I do make myself drink more consistently I feel better, my skin is better etc.

I think most people (as in average people) would be better off drinking more water.

This has happened to me on a few occasions after a high TSS workout (200K rides). I researched it a bit and it’s basically your body trying to protect itself by holding on / stocking up on fluids. I noticed that I gained at least 3 kilos of weight in the days following and that about 3 days later I could not stop peeing :wink:
I thought I had hydrated properly during the ride but maybe not enough.

To be fair, I usually don’t get thirsty unless I am desperately thirsty, either, so I also force fluids on the trainer :wink: Just as a general rule in our daily lives, I think drinking when thirsty (or when you have other signs, like pee the color of goldenrod) is just fine, for most people.

And less IPA. :wink:

And that has been my problem…at ultra distance events. I don’t actually need (need as in performance impacting dehydration) water until I go past 5 or 6 hrs. I’ll want it all right but I won’t fall apart.

Noakes’ work pointed out particularly to marathon runners that the idea they must drink water all the time was false. He found that marathon runners could finish with zero performance degradation without touching a drop.

In one of Matt Fitzgeralds’ books (race weight?) he mentioned a study that showed that he fastest finishers in the NYC marathon (or some other marathon) were the most dehydrated of the finishers they tested.

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Thanks for the replies all. Some interesting links to follow and lines of enquiry to pursue. I guess the main takeaway is to think about it less and accept that if my body is most receptive to fluid under a light load, so be it. I’m definitely going to keep adding a few minutes and an extra bottle to my warm up.



Is this not just a tiny element of the bigger picture though? Organ function, skin and other stuff (you can tell I’m no expert right?) :smile: