Training & Nutrition - Coffee & Wine & Dehydration

I drink a reasonable amount of water generally speaking.

I have a hypothetical question.

Let’s say my wife and I share a bottle of wine in the evening. I go to bed. I wake up the next morning and have one large cup of coffee (12oz).

For almost 12 hours I’ve had no water and have been drinking alcohol and caffeine: not huge amounts but enough to question just how dehydrated they make me.

It’s a general question and probably hard to get an answer, but is there anyone out there with any insight? Something like, “for every cup of coffee you drink you should drink an extra xxx amount of water”

I ask because my winter routine is I wake up, drink coffee, eat oatmeal, and hit the trainer. I always find myself on the trainer thinking, “man, I bet I don’t have enough water in my system”

This question is impossible to answer exactly as you wish, because everyone makes their coffee different strengths, uses different coffee beans, drinks different types of wine, etc. However, I believe generally, you gain the volume you drink in water (cuz even wine and coffee are mostly water), And lose a slightly larger volume due to the diuretic effects of the drinks. So the general rule is that for every drink you have (alcoholic or coffee), you should drink about an 8oz. glass of water to stay ahead of the diuretic effects of the drink.

I'd recommend also having a glass of water before you go to bed at night, and another in the morning in addition to your coffee and oatmeal. This will help you with the dehydration caused by wine/coffee, and it's very good for your system, as well. Most people have heart attacks and strokes in the morning, because they're dehydrated, and their blood is thick, making it harder to pump and distribute. By hydrating yourself right before you go to bed and as soon as you wake up, you minimize the time that you essentially have "thick blood," and make it easier on your heart and circulatory system to do what it's gotta do, especially when you're exerting yourself.

Hope this helps! :)

I figure coffee is mainly water, so I just drink more coffee.

Latest research shows that coffee, Coke, etc., do not dehydrate you. They don't hydrate you as much as plain water, but they definitely do not dehydrate you. Wine doesn't dehydrate you either. Weigh yourself in the morning after drinking a 1/2 bottle. You'll be a little heavier than if you hadn't drunk the wine, i.e. no dehydration, in fact probably the opposite. So don't worry about it. Have your coffee and ride. If you're thirsty, drink. If not, not.

Latest research shows that coffee, Coke, etc., do not dehydrate you. They don't hydrate you as much as plain water, but they definitely do not dehydrate you. Wine doesn't dehydrate you either. Weigh yourself in the morning after drinking a 1/2 bottle. You'll be a little heavier than if you hadn't drunk the wine, i.e. no dehydration, in fact probably the opposite. So don't worry about it. Have your coffee and ride. If you're thirsty, drink. If not, not.

Cut it out with the misinformation. This is downright bad logic. Coffee is a diuretic, as is alcohol. Alcohol to a worse extent. Try drinking a six pack before bed, and than going directly asleep with no water. Do the same with a couple tall glasses of water the next night and note the hangovers for each morning after. I guarentee the morning where you drank water the night before will have much less hangover symptoms.

To the OP, I'd recommend drinking a cup or two of water after the wine, and same after the coffee.

There used to be a time where I only drank coffee during the day and beer at night. I didn't shrivel up.

Doesn't mean it's not bad for you.

Cut it out with the misinformation. This is downright bad logic. Coffee is a diuretic, as is alcohol. Alcohol to a worse extent. Try drinking a six pack before bed, and than going directly asleep with no water. Do the same with a couple tall glasses of water the next night and note the hangovers for each morning after. I guarentee the morning where you drank water the night before will have much less hangover symptoms.

To the OP, I'd recommend drinking a cup or two of water after the wine, and same after the coffee.Andre: If you're going to be nasty, please furnish a link to a controlled study to show I'm wrong.

Not cherry-picking here, these are just the top google links:
http://advance.uconn.edu/2002/020722/02072207.htm
http://www.pponline.co.uk/encyc/caffeine-dehydration.htm
http://www.mckinley.uiuc.edu/Handouts/caffeine.html
http://www.bioline.org.br/request?np05019
http://www.ajcn.org/cgi/reprint/32/4/817.pdf

"In fact, caffeine is no more a diuretic than water"
"No diuretic effect of alcohol was detected in any of the subjects."

One gets a hangover because one has experienced alcohol poisoning, not from dehydration. (:-)>

I drink a reasonable amount of water generally speaking.

I have a hypothetical question.

Let’s say my wife and I share a bottle of wine in the evening. I go to bed. I wake up the next morning and have one large cup of coffee (12oz).

For almost 12 hours I’ve had no water and have been drinking alcohol and caffeine: not huge amounts but enough to question just how dehydrated they make me.

It’s a general question and probably hard to get an answer, but is there anyone out there with any insight? Something like, “for every cup of coffee you drink you should drink an extra xxx amount of water”

I ask because my winter routine is I wake up, drink coffee, eat oatmeal, and hit the trainer. I always find myself on the trainer thinking, “man, I bet I don’t have enough water in my system”

I have one of those scales that measures weight, body fat and hydration level. I am always on the low side on hydration in the morning even though I drink 8-12 oz during the night. I have wine in the evening, coffee in the morning but drink enough water (as well as fruit and veggies with water content) during the day so that I am fully hydrated in the evening. I suspect that you are probably slightly dehydrated when you hit the trainer in the morning. Just drink some water during your trainer session, and if you drink water throughout the day, I wouldn't worry. That said, we are all different. It is a fact that women have more fluctuation in water content than men. The scale with the hydration level measurement is very cool. The instructions with the scale warn that drinking coffee or alcohol will affect the readings (also the body fat readings - because it uses bioelectrical impedance analysis, if yiu have low hydration, the body fat reading is higher.

Going to try to drink some water before bed. Might even mix in a bit of Cytomax for good measure.

You know what else I've noticed, the alcohol raises my body temperature and causes me to sweat. I'll wake up in the early morning with an urge to go to the bathroom and find I'm sweating. If I don't drink wine, this doesn't happen.

Must be loosing water here too.

I can't answer your question but I have a rule for myself - the first thing to hit my stomach in the morning is a large glass of pure water. Then I enjoy my caffeine. :)
Try it. It will keep you from wondering.

Andre: If you're going to be nasty, please furnish a link to a controlled study to show I'm wrong.

Not cherry-picking here, these are just the top google links:
http://advance.uconn.edu/2002/020722/02072207.htm
http://www.pponline.co.uk/encyc/caffeine-dehydration.htm
http://www.mckinley.uiuc.edu/Handouts/caffeine.html
http://www.bioline.org.br/request?np05019
http://www.ajcn.org/cgi/reprint/32/4/817.pdf

"In fact, caffeine is no more a diuretic than water"
"No diuretic effect of alcohol was detected in any of the subjects."

One gets a hangover because one has experienced alcohol poisoning, not from dehydration. (:-)>

The BBC reported on this last year (or was it the year before?). It's changed a lot of people's misconceptions about caffeine and alcohol. Sadly, many people still believe the myths....

Alcohol suppresses Anti Diuretic Hormone (ADH), and is dehydrating for that reason. This is well known, not a myth, and supported by the links above.

Please be careful about the information you post, as misinformation regarding hydration could cause someone harm in the wrong conditions (i.e. consuming alcohol when dehydrated on a hot day, etc.).

Andre: If you're going to be nasty, please furnish a link to a controlled study to show I'm wrong.

Not cherry-picking here, these are just the top google links:
http://www.bioline.org.br/request?np05019
http://www.ajcn.org/cgi/reprint/32/4/817.pdf

"In fact, caffeine is no more a diuretic than water"
"No diuretic effect of alcohol was detected in any of the subjects."

One gets a hangover because one has experienced alcohol poisoning, not from dehydration. (:-)>

The 2 studies show that there is an diuretic effect from alcohol and caffeine. The studies are also far from conclusive. In AJCN n=6, which means one anomaly can throw off the results, the internal validity seems to be questionable in that study. The Nigerian students drank 1.5L of fluid in 5 minutes and it indicated that the diuresis started earlier than that of water. Again the internal validity is in question, it did not show that the caffeine concentrations were the same across the board, just that the tea was diluted to 1.5 L. They also noted in the Nigerian study that the diuresis started 30 minutes earlier with the palm wine and the tea. The study also postulated that a large volume of water will also suppress the secretion of ADH. There were also findings that there were differences in the pH of the urine between the fluids, but it does not mention what the pH of the fluids were or the pH of the urine before the test. As well, if the people in the Nigerian study were regular consumers of caffeine they would have built up a tollerance to the drug. The study did not say whether regular caffeine use would disqualify someone from the study.

In the AJCN the chart showed that there was more sodium and potassium lost with the ingestion of ETOH. In the case of K and ETOH, there was a negative K balance. Fecal losses were the same, but there is clear evidence even with the weak internal validity, that there were greater Na and K losses when alcohol was consumed. The blood alcohol level was also very low at 0.02, barely enough to even have a perceptible effect. A person who gets severely intoxicated from ETOH will have a blood ETOH level much higher than 0.02

As for anecdotal evidence, why is it that so many people crave salt after a night of drinking? Or that if you are drinking and consume something with lots of salt in it before passing out your hangover is not as bad?

I left out the other reports because they are interpretations of studies. But one did say that caffeine has a mild diuretic effect that is lessened with more caffeine use. This shows tollerance to a drug, which happens in most cases after habitual use. If the habitual user were to up the caffeine intake from the baseline they would again start to experience the diuretic effects.

Latest research shows that coffee, Coke, etc., do not dehydrate you. They don't hydrate you as much as plain water, but they definitely do not dehydrate you. Wine doesn't dehydrate you either. Weigh yourself in the morning after drinking a 1/2 bottle. You'll be a little heavier than if you hadn't drunk the wine, i.e. no dehydration, in fact probably the opposite. So don't worry about it. Have your coffee and ride. If you're thirsty, drink. If not, not.

It is now understood that caffeine is not a diuretic unless taken in very large quantities. However, alcohol is. Ryan in Nutrition for Endurance Athletes (2nd edition) has a rule to drink so many ounces of water for each ounce of alcohol consumed.

Al

Check your pee folks. Light, clear, dilute urine, you are good to go. Seriously, the color is a great way to gauge your hydration status.

I am fascinated by the latest studies that say Gatorade and equivalents(unless you are trying to correct a pretty severe electrolyte shortage) are a bad idea because it "fakes out" the kidney's natural protective mechanism / feedback loop. My understanding is that your kidney will conserve electrolytes appropriately but if you are drinking salt water, then this mechanism never kicks in... I think of it somewhat like the hypoglycemia following a sugar rush.

(I'll look for the link if anyone is interested (or maybe you guys already know this and are thinking "duh") Or perhaps I am wrong, but a well known published boxing trainer told me and even sent me the studies which I skimmed.

The theories are all very interesting, but the real question you are asking is are you dehydrated when you ride the trainer.

Very easy answer, you won't be dehydrated if you drink water till you pee clear/straw color. Wake up and start drinking water and don't ride until your pee test is good.

edit-oops, I should read the post directly above mine before I post, shouldn't I?

It is now understood that caffeine is not a diuretic unless taken in very large quantities. However, alcohol is. Ryan in Nutrition for Endurance Athletes (2nd edition) has a rule to drink so many ounces of water for each ounce of alcohol consumed.

Al

How much caffeine, though? Personally speaking, green tea doesn't necessarily give me a noticeable diuretic effect, but if I have two cups of strong coffee, I'm definitely peeing more and more often than if I had been drinking water.

PS sorry to carbonfiberboy for my bitter post above.

How much caffeine, though? Personally speaking, green tea doesn't necessarily give me a noticeable diuretic effect, but if I have two cups of strong coffee, I'm definitely peeing more and more often than if I had been drinking water.

It is too simplistic to say that coffee is not a diuretic. It varies between individuals and what is in their stomach at the time they consume caffeine. If you drink coffee in the morning on an empty stomach and put sugar in it, there will me more of a diuretic effect then if you drank it with lots of cream and no sugar in the middle of the day after eating a full meal.

Just like many drugs, if you take it on an empty stomach mixed with something that will speed up transit time it will have a greater effect faster.

You have even noticed it yourself, and you probably know when you are pissing more than usual.

That being said at the agency that I work at coffee and tea is considered when we are recording intakes which we are supposed to keep above 1000ml/day. Most people who drink coffee usually drink it everyday and thus are not as affected by it.

If you feel like experimenting measure your coffee out and then measure your urine to see if you put out more than you take in.

Very easy answer, you won't be dehydrated if you drink water till you pee clear/straw color. Wake up and start drinking water and don't ride until your pee test is good.


worth repeating though.

simple methods work well in the field.:beer:

The Marines in 134 F degrees this summer in Fallujah use this method too, JB says.

I'm still waiting for the link to a study that shows definitely that caffeine or alcohol dehydrates you more then plain water. I think we can all agree that all three of those liquids cause some dehydration compared with saline solution. Just saying a thing doesn't make it true. I hope we try to be a reality-based community. My personal experience is the same as that of the studies to which I linked. Today before my ride, I drank 16 oz. of a breakfast drink (no salt), drank two cups of coffee, and took a 200 mg. caffeine pill. During the ride, I drank 20 oz. of fluid (no salt), and another cup of coffee. After the ride I drank 20 oz. of recovery drink and a pint of beer. The ride was over 3 hours. The day was about 50°. I peed once at mid ride, moderate amount, and once after returning home. My body weight was about the same as when I left. Doesn't sound like dehydration to me!

Well, the only real way to find out is to try it out on yourself. Take it to the limit and then assess your own limit :)

As for me, it was rather accidental. I had a rather big mug of coffee with breakfast, then I went on a bicycle wine tour of the wineries, drinking lots and lots of tasty free wine, bought a few bottles. It was about 2pm with the sun blazing overhead when I realized that I was bleeding profusely from my nose. Had to park the bike and take a nap in the shade :)

So there: coffee, wine, and dehydration (riding in the sun)

A no-no.

So I figure I can safely go for 2 out of 3. No problem so far.

How much caffeine, though? Personally speaking, green tea doesn't necessarily give me a noticeable diuretic effect, but if I have two cups of strong coffee, I'm definitely peeing more and more often than if I had been drinking water.

PS sorry to carbonfiberboy for my bitter post above.



I had to check Ryan. She refers to studies showing no additional dehydration due to caffeine then states "Endurance Athletes can rest assured that a moderate intake of caffeine of about 1.4 to 2.7 milligrams per pound of body weight daily should not compromise their daily hydration status when consumed within the context of a well balanced diet."

On Alcohol she points out that the intake of alcohol has no place in the diet of an endurance athlete. It interferes with the body's ability to use vitamins and minerals, is metabolized as fat and can interfere with glycogen synthesis. Also, having four or more drinks daily raises the odds of developing obesity by 46%.

Al

I'm still waiting for the link to a study that shows definitely that caffeine or alcohol dehydrates you more then plain water.

I tried, but I couldn't link to my textbooks. However, the links given above that question caffiene's diuretic effects do confirm that alcohol does produce diureses, and it is well known...part of the education of every medical professional. Plain water may make an excess of fluids, which you will get rid of, but does not produce diuresis - these are two different things.

Our kidneys always pull H2O out of our blood, at all times. A specific hormone (ADH) causes it to be reabsorbed, based on our bodies perceived need for fluids. Alcohol suppresses ADH, and causes dehydration in proportion to the amount of alcohol present. It happens every single time you drink alcohol.

Trust me. ;)

The theories are all very interesting, but the real question you are asking is are you dehydrated when you ride the trainer.

Very easy answer, you won't be dehydrated if you drink water till you pee clear/straw color. Wake up and start drinking water and don't ride until your pee test is good.

at last, a decent answer to make it simple for everyone..

at last, a decent answer to make it simple for everyone..Fortunately for the OP, it doesn't make the slightest difference. Just ride the friggin' trainer. Maybe have a quick cup of coffee first. There's actually no evidence that slight dehydration makes any performance difference. We all know it's impossible to rehydrate on a hot ride as quickly as one loses water. Yet we manage to ride just fine, don't we? Unless we're sick or don't drink the 25 oz./hr., that is. Don't believe me? Have a look around the web for the recent studies.

Ah, I did it for you:
http://209.85.173.104/search?q=cache:aq_K6ZFbgbkJ:cyclingresearchnews.com/News_Feed.php