# Exercise and water - some questions **URL:** \ **Category:** Factual Questions\ **Created:** [July 10, 2011, 3:06am UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477 "2011-07-10T03:06:15Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 10, 2011, 2:50pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/21 "2011-07-10T14:50:07Z")
A less med-speak article [on over-hydration](http://www.maynardlifeoutdoors.com/2010/02/avoid-overhydration-and-hyponatremia.html). > [@](#): > > DON’T overhydrate before, during, or after the ride. The popular dogma is “drink before you are thirsty.” The dogma is wrong, and potentially dangerous. With today’s cult of hydration, 5% to 20% of people completing endurance events will weigh more at the end than when they started! Studies have shown that when athletes drink to satisfy thirst they tend to replace only about 75% of the water they are losing during the endurance event. This, rather than drinking to not lose any weight, appears to be the safer target. Full recovery from the mild event-related dehydration will take place after the event is over. Overhydrating, i.e., gaining weight during the event, does not improve performance. > > The health risk from overhydration is that it lowers sodium concentration in the blood, i.e., hyponatremia. In that study mentioned above 10% of the athletes had gained weight by the end of the event, 3% had blood sodium below the normal range, and 1% had symptoms associated with low sodium. While puffy hands and ankles are not a serious health problem, swelling of the brain is! The problem here is that the brain is encased in a rigid container – the skull – and cannot expand. From mild to severe, the signs and symptoms of overhydration can include one or more of the following: headache, nausea, puffiness (face, ankles, hands), dizziness, confusion, agitation, vomiting, respiratory distress, stupor, coma, seizures, and (very, very rarely) death. Sports drinks do not contain enough sodium to prevent hyponatremia. > > Contributing to the incidence of overhydration is that fact that for some people, prolonged exercise turns off urine production even if they are overhydrated. The effect can continue for hours after exercise stopped. Thinking that “No pee” means dehydration, these people continue drinking water and sports drinks in an attempt to trigger urine production. ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [July 10, 2011, 5:03pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/22 "2011-07-10T17:03:34Z")
So what is the straight dope? I work a lot of festivals in the summer. It is often hot, humid, and in the afternoon, the sun is out. I am not working hard, mostly just walking around. I sweat profusely. I also drink lots of cold water. I may consume some salty junk food and a Dr Pepper. The water I drink doesn’t kill my thirst. I drag my dogs along too. I apply water to them externally. They are wilted by the end of the day. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 10, 2011, 6:54pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/23 "2011-07-10T18:54:39Z")
> [@thelabdude](#): > > So what is the straight dope? I work a lot of festivals in the summer. It is often hot, humid, and in the afternoon, the sun is out. I am not working hard, mostly just walking around. I sweat profusely. I also drink lots of cold water. I may consume some salty junk food and a Dr Pepper. The water I drink doesn’t kill my thirst. > > I drag my dogs along too. I apply water to them externally. They are wilted by the end of the day. If you are still thirsty you should drink more and bring a portable bowl to let your dogs have a drink every so often also. ---
**Author:** ![Ambivalid](https://avatars.discourse-cdn.com/v4/letter/a/a5b964/32.png) [@Ambivalid](https://boards.straightdope.com/u/Ambivalid)\ **Post date:** [July 10, 2011, 6:58pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/24 "2011-07-10T18:58:11Z")
> [@Princhester](#): > > Yes there is a lot of wrong information about this issue on the internet, your cite being a classic example. People are so proud of their ability to remember their high school physics they can’t wait to point out that calories must be burned to raise the temp of the water. The problem is that in their hurry to show off their basic physics, they overlook the crux of the question which is not whether calories are burned but whether extra calories are burned. > > The body is a net exporter of waste heat. As one would expect for a system honed towards efficiency by evolution, our body does nothing so stupid as to burn more calories to warm up, while at the same time giving off waste heat that it doesn’t have to. > > The first thing the body does when faced with cold is not burn more calories, it is to stop exhausting as much excess heat. > > The analogy that really brings it home is one thought up by another poster last time we discussed this topic: > > Imagine a car that drives from A to B and in doing so burns a certain amount of fuel. Now imagine that it does the same trip under precisely the same conditions, but with an ice cold can of coke sitting on the engine. When the car arrives at B it will have burned precisely the same amount of fuel, but the can will be warm. How so? Well, the cold can will cool the engine a little, and the thermostat will shut down ever so slightly, and some of the heat that would have been dissipated by the radiator will instead go into the can. > > Don’t worry that you got it wrong, so does every physics teacher I’ve heard talk about it, and even [our own Cecil](http://www.straightdope.com/columns/read/1253/is-it-possible-to-diet-with-beer). You can read a lot more about it by reading [this thread](http://boards.straightdope.com/sdmb/showthread.php?t=57799), amongst others. > > There is detailed information here:[http://www.mednote.dk/index.php/Thermoregulation,\_temperature\_and\_disorders](http://www.mednote.dk/index.php/Thermoregulation,_temperature_and_disorders). > > Read all the threads and that cite then come back and explain to me how sure you are that drinking cold water while exercising will burn more calories. The most you can say is that under some relatively unusual conditions some of the calories to warm the water will be extra calories burned for that purpose. > **[Redirect Notice](https://www.google.com/url?sa=t&source=web&cd=3&ved=0CCkQFjAC&url=http%3A%2F%2Fwww.chow.com%2Ffood-news%2F54270%2Fdoes-drinking-ice-water-burn-calories%2F&ei=yvIZTodFqLbQAe_FrJcF&usg=AFQjCNGMtoblgfEiFQjo3bk8b1-GrWYn1A)** I have found countless doctors, MDs, who have confirmed the theory that drinking cold water does in fact result in extra calorie burning. Calorie burning from the energy required to raise the temperature of the cold water. Now, I not saying this in the context of while one is exercising, just in general. AND, most importantly, the effects of such water ingestion are small and minor at best. My point was that the concept can be used successfully in a well-rounded weight loss plan. I know it was a bit of a thread hijack, and I apologize. ---
**Author:** ![emacknight](https://avatars.discourse-cdn.com/v4/letter/e/3ec8ea/32.png) [@emacknight](https://boards.straightdope.com/u/emacknight)\ **Post date:** [July 10, 2011, 7:23pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/25 "2011-07-10T19:23:09Z")
> [@Patch](#): > > Never been tested for diabetes. I’m only getting the thirst issue in the workout, not during the day. > > I’m doing cardio for 30-45 min, and lifting weights for about an hour-fifteen. Weigh yourself before and then after a workout (without wet clothes), the change should represent water loss where a pound is a pint. This should give you a pretty good indicator of how much liquid you need over the course of your workout. I think I lost 7 pounds over the course of an Ironman, and I’d typically lose 5 pounds on some longer bike rides. From that I knew I needed at least a pint per hour. Yesterday it was over 95 during a 2 hour run and I think I lost at least 2 pounds, meaning I’d needed another pint per hour beyond what I was consuming! Something I found helped was to take “sips” at regular intervals alternating between energy drink and water. What you need to consider in all this is that water lost includes a lot of electrolytes which needs to be balanced. ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [July 10, 2011, 7:30pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/26 "2011-07-10T19:30:30Z")
> [@DSeid](#): > > If you are still thirsty you should drink more and bring a portable bowl to let your dogs have a drink every so often also. I drink until my stomach says enough. The dogs get plenty of water plus ice. Also breaks in the shade. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [July 10, 2011, 9:37pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/27 "2011-07-10T21:37:43Z")
> [@R.P.McMurphy](#): > > **DSeid** ’s post is a bit technical but it does touch on how misguided the advice was to athletes in days gone past. Idiot coaches would tell athletes to swish water in their mouth and spit it out. Those coaches were idiots and should all spend some time in Hell. Hydration is important and 20-25 minutes can provide a benefit to the body. (A lot of athletic contests last longer than that). Hydrating during a contest, in moderation, is a good thing, not a bad thing. Even a few minutes is better than nothing. The coaches were not idiots, but just following the standard advice at the time. (This was the advice given to us when I was in high school over half a century ago.) Exercise physiology has come a long way since, but much of the “conventional wisdom” is now known to be wrong. As DSeid’s link notes, athletes were later advised to drink water before they get thirsty as thirst is a late symptom of dehydration. (I think this is still true, but one would not have to worry about slight dehydration as long as it is less than 2% dehydration, as DSeid notes). The advice now is not to drink until you are thirsty, but only because many instances of hyponatremia have been noted in endurance exercisers: those doing full triathlons, ultramarathons, etc. I believe cases have been noted in those doing just marathons, too. As DSeid noted, these exercisers were drinking just water, thereby diluting the sodium level in their blood. Most sports drinks contain some sodium. I’ve read, however, that Gatorade does not contain enough sodium. Which brings up the topic of salt tablets. Those were given in the military, and may still be given in the military. One or two salt tablets taken while drinking during endurance exercise may be a good idea. I don’t know, so I’d like DSeid to comment on that, please. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 10, 2011, 9:46pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/28 "2011-07-10T21:46:00Z")
From the guideline linked to in post #19 > [@](#): > > There is no currently available evidence to support the suggestion that Na + supplementation prevents the development of EAH 66,76 nor is there any evidence that consumption of electrolyte-containing hypotonic fluids (ie, sports drinks) can prevent the development of EAH in athletes who drink to excess. All sports drinks are hypotonic, not just Gatorade. ---
**Author:** ![Ambivalid](https://avatars.discourse-cdn.com/v4/letter/a/a5b964/32.png) [@Ambivalid](https://boards.straightdope.com/u/Ambivalid)\ **Post date:** [July 10, 2011, 9:52pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/29 "2011-07-10T21:52:08Z")
> [@DSeid](#): > > From the guideline linked to in post #19All sports drinks are hypotonic, not just Gatorade. I’m just curious, what is your opinion on the modest calorie-burning effects of drinking cold water; effects borne out of the increased energy needed by the body to raise the temperature of the water? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 10, 2011, 10:00pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/30 "2011-07-10T22:00:49Z")
Assuming that it is not merely used to cool off excess heat which would otherwise be radiated off, so modest as to be counted as zero. Now living and working in a cold environment is another story. ---
**Author:** ![Ambivalid](https://avatars.discourse-cdn.com/v4/letter/a/a5b964/32.png) [@Ambivalid](https://boards.straightdope.com/u/Ambivalid)\ **Post date:** [July 10, 2011, 10:14pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/31 "2011-07-10T22:14:15Z")
> [@DSeid](#): > > Assuming that it is not merely used to cool off excess heat which would otherwise be radiated off, so modest as to be counted as zero. Now living and working in a cold environment is another story. “so modest as to be counted as zero”…so you do acknowledge the extra energy IS exerted by the body. So does the amount of water consumed impact this level at all? Like if a person were to drink large, but safe, amounts of cold water (say 1-2 gallons per day), would the impact still be so modest as to be counted as zero? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 10, 2011, 11:34pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/32 "2011-07-10T23:34:24Z")
Again, note the first assumption. It’s a biggie under normal circumstances. Most of the time warming up that water would just be done instead of releasing that much additional heat via the skin. You’d have to be in an environment in which your body temperature was already dropping and trying to warm itself up, both cold and underdressed. And that is **Princhester** ’s very cogent point. Then move onto **Inner Stickler** ’s calculations which seem reasonable - 5 Cal for a cold 8 oz glass. Essentially zero. Even 2 gallons would then come to only 80 Cal. Maybe not zero but still fewer calories than in an apple. ---
**Author:** ![Ambivalid](https://avatars.discourse-cdn.com/v4/letter/a/a5b964/32.png) [@Ambivalid](https://boards.straightdope.com/u/Ambivalid)\ **Post date:** [July 10, 2011, 11:52pm UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/33 "2011-07-10T23:52:35Z")
> [@DSeid](#): > > Again, note the first assumption. It’s a biggie under normal circumstances. Most of the time warming up that water would just be done instead of releasing that much additional heat via the skin. You’d have to be in an environment in which your body temperature was already dropping and trying to warm itself up, both cold and underdressed. And that is **Princhester** ’s very cogent point. > > Then move onto **Inner Stickler** ’s calculations which seem reasonable - 5 Cal for a cold 8 oz glass. Essentially zero. Even 2 gallons would then come to only 80 Cal. Maybe not zero but still fewer calories than in an apple. “Now it’s a minor effect but when combined with a well-rounded plan it is a good idea, imo.”-This was my original point and I believe you somewhat confirmed it. A well-rounded plan for weight-loss should include lots of water. If you can roughly add the amount of extra calories you burn in a day in the amount of say an apple by doing nothing more than chilling your water, I’d say that was a pretty win-win move. Nothing to lose, little bit to gain. ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [July 11, 2011, 4:24am UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/34 "2011-07-11T04:24:01Z")
> [@jamiemcgarry](#): > > “Now it’s a minor effect but when combined with a well-rounded plan it is a good idea, imo.”-This was my original point and I believe you somewhat confirmed it. A well-rounded plan for weight-loss should include lots of water. If you can roughly add the amount of extra calories you burn in a day in the amount of say an apple by doing nothing more than chilling your water, I’d say that was a pretty win-win move. Nothing to lose, little bit to gain. \*\*DSeid \*\*is only saying you will burn extra _if_ you are cold and underdressed when you introduce the additional heat stressor of a cold drink. Your plan will achieve nothing at all unless you intend to spend your weight-loss program time being cold and underdressed. And if that’s what you plan on doing, then you probably don’t need to worry about the cold drink. Frankly, most people trying to achieve weight loss have a hard enough time trying to keep up the exercise and not give in to hunger. The whole shtick about drinking cold water is something people suggest as an “easy” thing to do. As such, it’s a furphy because it is only going to work if you make yourself uncomfortably cold. So it’s not going to be easy at all. Not only that, but the truly inane aspect is that the only way you are going to keep yourself cold enough to ensure that drinking cold water will burn extra calories is by being cold and _not doing any exercise_ while the drink is warming up within you. Even an extremely low level of activity is going to produce enough waste heat to negate the effect. So you have the option of getting yourself uncomfortably cold, taking off your clothes in a cool environment, drinking 2 gallons of water (ie enough to make yourself slosh like a bathtub) then standing around stock still shivering for a good long while till the water warms up. Or you can spend the same time engaged in very moderate normal activity and probably burn far more than 80 calories. ---
**Author:** ![Inner\_Stickler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inner_stickler/32/318_2.png) [@Inner\_Stickler](https://boards.straightdope.com/u/Inner_Stickler)\ **Post date:** [July 11, 2011, 5:52am UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/35 "2011-07-11T05:52:56Z")
Me, I’m just not going to eat the gummi bears. ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [July 11, 2011, 6:08am UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/36 "2011-07-11T06:08:07Z")
> [@Inner\_Stickler](#): > > Me, I’m just not going to eat the gummi bears. It’s OK if they are straight out of the freezer. Well, unless you break a tooth on them. ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [July 11, 2011, 6:11am UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/37 "2011-07-11T06:11:33Z")
> [@DSeid](#): > > Even 2 gallons would then come to only 80 Cal. Maybe not zero but still fewer calories than in an apple. > [@jamiemcgarry](#): > > “Now it’s a minor effect but when combined with a well-rounded plan it is a good idea, imo.”-This was my original point and I believe you somewhat confirmed it. A well-rounded plan for weight-loss should include lots of water. If you can roughly add the amount of extra calories you burn in a day in the amount of say an apple by doing nothing more than chilling your water, I’d say that was a pretty win-win move. Nothing to lose, little bit to gain. Who drinks over 2 gallons of water a day, besides you? ---
**Author:** ![Ambivalid](https://avatars.discourse-cdn.com/v4/letter/a/a5b964/32.png) [@Ambivalid](https://boards.straightdope.com/u/Ambivalid)\ **Post date:** [July 11, 2011, 6:19am UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/38 "2011-07-11T06:19:59Z")
> [@needscoffee](#): > > Who drinks over 2 gallons of water a day, besides you? I don’t drink that much water. All I’m saying is chilling your water has a moderately positive effect when trying to lose weight. When combining the myriad other physical and nutrional components that one does in a effort to lose weight, this is one effortless (albeit tiny) piece that can help. ---
**Author:** ![Inner\_Stickler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inner_stickler/32/318_2.png) [@Inner\_Stickler](https://boards.straightdope.com/u/Inner_Stickler)\ **Post date:** [July 11, 2011, 6:29am UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/39 "2011-07-11T06:29:44Z")
Well, if you’re going that route, you might as well chill all your food and drink, no? ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [July 11, 2011, 7:09am UTC](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477/40 "2011-07-11T07:09:50Z")
> [@jamiemcgarry](#): > > I don’t drink that much water. All I’m saying is chilling your water has a moderately positive effect when trying to lose weight. When combining the myriad other physical and nutrional components that one does in a effort to lose weight, this is one effortless (albeit tiny) piece that can help. **IF** it burned 5 cals per glass, which is questionable, then 600 glasses of water later, a person has burned one pound’s worth of calories. “Moderately positive” or even “tiny” doesn’t begin to describe it. And don’t forget that room temperature water is also colder than body temp. and as such would cause you to burn some amount of calories raising it to body temperature, if that theory is correct. Ice water would be brought up 66F degrees; room temp water would be brought up 28F degrees, or 42% as much, or 2 calories burned per glass of room temperature water. So 3 calories/glass difference between ice water and room temp water. [Previous page](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477.md?page=1) [Next page](https://boards.straightdope.com/t/exercise-and-water-some-questions/588477.md?page=3)