Dehydration associated with poorer performance on attention tasks among adults
onlinelibrary.wiley.com
onlinelibrary.wiley.com
"Staying hydrated" means to match the body's needs, not more, not less. Like with all other silly hypes (antioxidants, electrolytes, vitamin supplements, etc. etc.), too much is potentially harmful. It is a hype, because it's so easy to say "stay hydrated" and it seems like an uncontroversial thing, but it can be just as harmful as dehydration. In fact, among e.g. long distance runners, severe complications from overhydration are more common than severe complications from dehydration.
Drinking too much water is harmful. Drinking too little water is harmful. You want a proper hydration balance, and in most circumstances—with several exceptions—this is well regulated by thirst. All of this is well documented and none of this is should be controversial at all.
I drink water because I want to? It’s not exactly being thirsty (I sometimes get thirsty when I’m out and about for extended periods; that feels different). It’s just wanting to drink water, and water being there. Should I be worried? Should I be limiting myself to only drinking water when I feel truly thirty?
I’m also an amateur marathon runner, and I reckon I probably drink much less liquid while running a marathon than in a comparable 3.5 hour block working (although I drink a lot of water and sports drink after finishing).
Edit: In case it matters, I don’t drink water because I’ve bought into “stay hydrated” hype. I’m well aware that I drink more than enough water to meet my body’s needs. I just like it.
Bad habit, sorry. I'm probably a lot more humble and open to being wrong than I seem, promise.
What I'm trying to say is that in most circumstances, with several notable exceptions, the body will self regulate these things perfectly fine, and most people in most cases don't have to actively "stay hydrated". Exceptions apply. Drinking ±6 liters throughout a work day sounds a lot to me, but I am in no way qualified to judge, authoritative tone or not :)
I do not know how big the margins are. What I do know is that two of my friends have needed medical attention (routine stuff) for urinary tract issues due to prolonged excessive water consumption, because they were trying to "stay hydrated". There's also been several medical professionals, i.e. doctors and researchers, warning about "stay hydrated" campaigns run by bottled water companies in my country. I don't know if it's as big a thing in other countries.
English is my third language, so sorry if the things I write are unclear.
Anyway, thanks for engaging!
Granted the pressures for dehydration are a lot more common (hiking with too little water, running competitions, maybe little access to water in a hot climate, etc). Once one has ample access to water, I doubt there is much pressure to keep drinking to over-hydration.
With all that said: Yes, dehydration is probably more common. My point is simply that the goal is a good balance, not to drink excessively to "stay hydrated".
I’m in the Rocky Mtns, so it’s pretty dry up here with lots of unprepared people (maybe confirmation bias in my end).
> People's response to dehydration or over-hydration is not uniform.
Of course not, and I have hopefully stated clearly enough and frequently enough that I'm talking about a general rule to which there are many exceptions both ways.
Not OP but as someone who would regularly consume way too much water to the point it was causing me adverse effects, this is my experience:
When I was properly hydrated I'd still be mildly thirsty.
When I have been overhydrated I'd keep getting thirstier.
And when I was getting close to being on the dehydrated side I'd get mildly thirsty.
But when I would actually start getting dehydrated, the thirst stopped.
It sounds backwards and weird but it's a thing and it's really quite problematic (and it's not that uncommon). I think it technically falls under the name polydipsia but it's more a symptom of any number of different biological quirks or disorders than anything specific in of itself.
When it comes to how one notices they are dehydrated when they aren't feeling thirsty, you tend to get good at picking up on the signs (skin turgor test, headaches, dry mouth, etc) and you also tend to be pretty cognizant of how much water you consume in a day which makes it pretty easy to self correct early.
This is not the case. It is very rare that I have ever felt thirsty. It has been an issue my entire life, often with seriously negative outcomes. Every day I have to make a conscious effort to ensure I drink enough water. I can never rely on how I feel; I always have to depend on what intake I have measured.
Also your source is an analysis of articles on water drinking advice, not a medical study.
Sorry to intrude with nothing more to contribute.
> Drinking too much water is harmful. Drinking too little water is harmful
Saying that too much something is harmful seems like an uncontroversial thing to say too. But you need to back it up with a source.
To the point of death? Sure. To the point of reduced functionality? I disagree. It's quite easy for me to feel thirsty, reach for my water bottle, realize it's empty, say ill get more water in a little bit, and then not get more water. Repeat 5 or so times and then a few hours go by and I start getting a headache.
My point is that in normal circumstances you don't have to drink unless you're feeling thirsty. Ignoring thirst causes some discomfort, because you're thirsty, will get headaches, cramps and so on and those symptoms will probably prompt you to drink. On the other hand, drinking too much generally doesn't lead to that much discomfort (unless you're drinking way too much), but will still be linked with various health risks.
I'd love if someone has a source, but I distinctly remember that a significant proportion of adults are constantly slightly dehydrated. Ironically, that might have been improved in recent times due to the Stanley cup (and various other water bottle) fads. It won't kill you, but it will cause inhibited cognition, and an increased risk of kidney stones.
Hydration is good. Extra electrolytes and water will be peed out.
...which is one of the easiest body signals to unconsciously ignore once your mind gets somewhat focused on anything, or to confuse with hunger.
On what do you base this claim? I think it's badly overstated. I'd say instead that it depends on circumstance. Seated in an air-conditioned office, you might be right. But if you are doing endurance athletics in a hot desert environment, it can be both easy and dangerous to drink too much plain water: https://www.trainingpeaks.com/blog/the-dangers-of-hyponatrem...
> Hyponatremia occurs in a substantial fraction of nonelite marathon runners and can be severe.
> As marathon running has surged in popularity during the past quarter-century, reports have emerged of serious illness and death from hyponatremia, as in the case of a 28-year-old woman who died after the 2002 Boston Marathon.
> Participants in the 2002 Boston Marathon were recruited … 488 runners (64 percent) provided a usable blood sample at the finish line. Thirteen percent had hyponatremia (a serum sodium concentration of 135 mmol per liter or less); 0.6 percent had critical hyponatremia (120 mmol per liter or less).
[1]: Hyponatremia among Runners in the Boston Marathon. https://www.nejm.org/doi/full/10.1056/NEJMoa043901
However, a 6-year study reported that exercise-associated hyponatremia, dehydration, and heat exhaustion occurred at nearly the same rate, prompting re-examination of emergency protocols. Most exercise-associated hyponatremia cases at the Grand Canyon occur among summer hikers to the inner Canyon and are often misdiagnosed as exertional heat illness due to overlapping signs and symptoms.
https://journals.lww.com/cjasn/fulltext/2024/05000/exercise_...
Hyponatremia is especially dangerous because a common response is to drink even more water, which makes the condition even worse. The National Park Service changed all their hiking advice to explicitly recommend "salty snacks" and "sports drinks".
I notice very few effects of "under-drinking". So yeah, not everyone has the same needs.
On the flip side, I was working outdoors in the sun all day today, and probably ended up drinking about 2 gallons of water without needing to pee much. So not everyone has the same needs even on a day to day basis.
I’ve also lived extensively over 9,000ft in altitude. Are we getting into a height pissing contest? If so, why?
Just drink water. Fucksakes.
A lot more than I ever realized.
There are also symptoms that turn out to be dehydration and not something you end up getting medicated for.
Making sure one’s hydrated, especially for the brain at least helps the brain and body be at its capable baseline before addressing further.
I recently started 1L of water first thing in the morning with a pack of electrolyte like a biosteel. The key is to drink at the pace that doesn’t make you pee, which seems possible in the morning. My understanding is most ppl wake up dehydrated after sleep.
It was noticeable after a few days and let me delay and eliminate the first caffeine and progressively push it to later in the morning.
Might not be for everyone but it would be surprising if more than a few people didn’t discover they might be a little dehydrated.
Caffiene is back to being a boost.
older people gradually lose their ability to sense thirst.
So, if you're older, you can be dehydrated but not feel thirsty.
I suspect the practical solution to this is to drink more all the time.
But I also think there's probably a market for some way of letting older people monitor their hydration status, maybe through a watch or other sensor.
I've always been deliberate about having sufficient water intake, but supplementing electrolytes on top of that made a small, but noticeable, difference. I take a small amount by pill w/each meal (along w/a multi-vitamin, etc.), and via powder form in my water or beverage once a day. I feel more refreshed and focused while at work or at the gym, and I no longer experience muscle cramps (I never had them frequently, but being deliberate about electrolyte intake has removed them entirely).
So, while the study focused on 'hydration', it's worth remembering that doesn't comprise of water intake alone. My performance and focus on sufficient water intake, while ok, felt inferior compared to sufficient water intake + electrolyte supplementation.
You’ll want the WHO recipe for Oral Rehydration Salts:
https://rehydrate.org/solutions/homemade.htm#recipe
Preparing 1 (one) Litre solution using Salt, Sugar and Water at Home Mix an oral rehydration solution using the following recipe. Ingredients:
2T Sugar
Half (1/2) level teaspoon of Salt
One Litre of clean drinking or boiled water and then cooled - 5 cupfuls (each cup about 200 ml.)
Preparation Method:
Stir the mixture till the salt and sugar dissolve.
> An electrolyte is a medium containing ions that are electrically conductive through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water.[0]
Probably no more or even less processed sugar than packaged and processed electrolyte offerings.
I always have a handful of these on me when I travel. Good if you get food poisoning or a hangover.
Plus they just taste good with a few squirts of water flavoring and some ice.
Examples: Salt; Potassium citrate; Magnesium citrate.
Another source of potassium is "low sodium salt". This is often the cheapest form of potassium you can easily get.
I wonder if other factors like glucose level could affect both osmolality and cognition?
Would be much more interesting as a randomized trial (though I'm not sure what would make a good placebo intervention as a control).
If my system 2 is able to intercept this processing and logically hypothesize- try plain water first- after starting to drink water I then realize I am very thirsty, and will consume 24-32 oz very quickly. Afterwards I feel great, re-energized.
But my body/autonomous system 1 still hasn't learned this, and it has now been a few years since first making this realization. So odd.
Hunger as a response to mild dehydration makes sense though. We get a significant proportion of our water intake from food. That instinct doesn't work quite as well in our engineered era of potato chips, but that's a recent problem.
This is truer than I used to think. Our dogs are mostly on a raw diet - some days I don't even see the older one drink water, or just once (the younger one is still an idiot puppy so runs around and goes to the toilet a lot more and has to top up). When we look after dogs on a kibble diet, it's amazing how much they drink in comparison.
Most of the time when your stomach starts to "grumble" you might be surprised how often it's thirst and not hunger.
Personally I wake up and I feel "starving", but the reality is that I'm just really thirsty because I haven't had any water for 6-8 hours.
You can go weeks without food, but typically can only last a day or two at a absolute maximum without water.
So I have trouble differentiating these. The trick is to figure out which ones you're least susceptible to. For me it's hunger. So when I consciously feel that tired/hungry/thirsty feeling, I know it's sleep or thirst, and based on how you slept, you can usually deduce whether you need a nap or glass of water.
n=2
He cites more evidence showing that even moderate dehydration (when you aren’t thirsty) leads to lower performance (mental and physical). And talks about overhydration and hyponatremia. IIRC also discusses how hydrating at different times of day affects you, turns out your kidneys dump water quickly if you drink too late. So hydrate before six.
Now, I can definitely tell when I haven't had enough. I used to think it was hangry, but I now can tell the difference.
So if you drink a dilute coffee (ex: weak iced milk base coffee drinks), you are probably fine but if you are drinking plain, hot coffee or low milk espresso drinks and you are sensitive to caffeine's diuretic properties, you are probably going to lose more than you gain.
There isn’t any science to support that. Feel free to only drink hot coffee for 3 days and see if you die of dehydration… Maybe you even think it's 2 days since hot coffee is even worse for hydration than nothing, apparently...
The public bathrooms in Japan on the other hand are a fantastical heaven.
And (at least in the mens room) leave the seat up unless you need it, and if you use it, put it up when you're done. That keeps it clean for the next person.
Not to mention I always leave the airpods in when I go now and have to triple check I’m on mute :)
1. Mute myself. 2. Double check I am muted. 3. Ask, "Can anyone hear me?" 4. Ask, "Can anyone hear me?" again, louder. 5. State, "I'm about to urinate."
Increasingly embarrassing failsafes, but not as embarrassing as broadcasting a bathroom break. I'm happy that I never needed anything past layer 2.
Someone asked where some background noise was coming from. I said "not from me, I'm on mute". And several people said "no you're not!"
On the plus side, it does force you to take the recommended breaks from sitting in front of a screen.
People that have calendars packed with meetings will have a hard time with bio breaks regardless of where they work.
I’m fortunate enough to work for a company that has a culture of minimal meetings for ICs (I probably average 4-6 hours per week), so bio breaks aren’t an issue.
But I should still be better about hydrating. I do better than some, but could still do better (probably 80 oz. per day).
I actually find this one minimally objectionable. I am a meat robot and I must attend to biological necessities. This is a convenient abstraction for my working relationships.
Taking a shit is a pleasure, the meeting is the inconvenience.
https://www.merriam-webster.com/wordplay/bio-break-meaning-a...
It is however unequivocally true that I much, much prefer going to the bathroom at home.