When Too Much Water Can Cause Problems for Runners

By , SparkPeople Blogger
For many runners, our biggest concern after injury, is becoming dehydrated, especially when temperatures start to sore and our mileage begins to creep up. While dehydration can be an issue, overhydration can be an even more dangerous issue, particularly in endurance athletes, such as marathon runners and tri-athletes.

Overhydration occurs when we drink too much water hence flooding our bloodstream with excess fluid. In doing so, we throw our electrolytes out of balance which can lead to deadly consequences if we do not recognize the warning signs early. And this issue does not just affect new runners. In an April 2005 report published in the New England Journal of Medicine, 13% of all runners who ran the Boston Marathon in 2002, had hyponatremia, or low blood sodium, due to overhydration.

The word is slowly getting around to runners of all levels to pay special attention to hydration. Even race directors are stressing awareness of overhydration and the need to monitor fluid intake with output, especially in the longer races.

Oddly enough slow, female runners are most susceptible to falling prey to overhydration. Some experts believe this is due to the longer time it takes them to run the course, therefore it allows them ample time to hit the water stations. And because the symptoms of overhydration, such as muscle cramps, lethargy, and confusion, can mimic those of dehydration, it isn't uncommon for runners to mistake the two causing the runner to take in even more fluid.

So what are the signs of overhydration?
  • Swelling of the fingers and wrist (tight watch) can be one of the first tell-tale signs that you are flooding your body with too much water.
  • Nausea, vomiting and bloating of the stomach.
  • Progressively worsening headache-this is due in part to the brain swelling due to the excess fluid.
  • Confusion, 'not feeling right' and irritability
  • Muscle cramps
  • Seizures and ultimately death if the symptoms of overhydration are not recognized early enough.

As a runner it is very important to monitor your fluid intake and output. Measuring your sweat rate is a great way to do so. To measure your sweat rate you should weigh yourself without clothing before your run, then run for an hour and then immediately after your run, weigh yourself again without your clothing and without drinking. For every pound you lose, you will want to consume 16 ounces of fluid over the course of the day. See the following link for a more in depth means of determining your sweat rate.

Many race directors of long distance races recommend writing your pre-run weight on the back of your bib. Should you become disoriented or confused during your race having this number can help determine whether this is a dehydration issue or an overhydration issue.

Because many of us have been indoctrinated to drink, drink, drink to avoid dehydration, the new trend being touted by running coaches, running experts, and organizations such as the United States Track and Field, is to have runners drink to thirst in other words DO NOT FORCE YOURSELF TO DRINK. And if you can choose a sports drink over water, however note that these will not prevent one from developing overhydration if you drink more fluid than your body needs.

According to Dr. Tim Noakes, author of the Lore of Running "Everyone becomes dehydrated in a race. But I have not found one death of a runner from dehydration in a competitive race in the entire history of running. Not one. Not even a case of illness." But the same cannot be said about overhydration which is why awareness and educating runners is essential to keeping us all safe.

Have you heard of overhydration or water intoxication? Were you aware of the dangers drinking too water much can cause? Are you surprised that this issue is not more on the forefront?

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RAZZOOZLE 1/29/2020
thank you Report
I have heard of this... for me dehydration gives me a migraine... but I would rather have a migraine than be dead... Report
Awesome...thanks! Report
Thanks. Report
Feeling much better after cutting back on water and letting my body tell my mind when it needs a drink. Happy not to be running to a toilet all day long. My body does not need 8- 8oz a day. Too much for me. Feel like I use to feel before I bought into this drink water constantly business. Report
I recently heard of this after a news report of a women dying after drinking a day's worth of water in under an hour while on a well-known and advertised diet here in the UK. Appparently the diet's creators didn't warn that the water was to be drunk over the course of the day.
It is terribly sad that this happened. We need to remember that when we say everything in moderation, this includes water! Report
So, essentially how much water is too much? Is it different for every person? I have pretty much stuck to 12 cups on most days. Eight for a normal day and the extra 4 on days I workout. Since I sweat alot, I think I am probably getting the right amount. Report
It's funny that you have brought this up. I heard about this issue this summer while training for my century bike ride. I started reading about proper re-hydration. From everything I've read and practiced you need to try to intake 1/3 of your fuel/liquid per hour. I started using Hammer Nutrition products and have been in better control of my hydration/fuel. The electrolyte balance is crucial to keep the motor running throughout any endurance activity. Report
very interesting... my question is this - if you stretch out the water over the course of the day - as long as you don't have those symptoms, then drinking plenty of water still ok?

I'm 5'4" and am a maintainer between 108-112 - and I drink 12-14 glasses of water EVERY day - there's never a day I have less than 12... and some days when I would work at the Farmer's market, I'd sometimes drink up to 20-22 glasses (would only work once a week so that wasn't an every day thing)

Water is my liquid of choice - no tea, pops ect for me...

I wanted to edit this and add that the 12-14 glasses of water I drink every day are spread out through out the day - averaging less than 1 glass an hour... Report

Because our weight, gender, body composition, the speed at which we run, our sweat rate, temperature and humidity, etc, varies, it is very difficult to have a so-call standard. I have read that drinking 4 ounces every 15 minutes or so may work for some, but for others that may not be enough. This is where calculating your sweat rate comes into play. If you lost say 1.5 pounds during on hour long run (without re-hydrating) you should be safe to drink 4-5 ounces slowly over the course of your run. I hope this helps. Report
I think what's needed now is information on the range of water consumption that is appropriate. Thanks for the information! Report
I read once that you didn't really need 8 glasses a day because you get water during the day from different sources such as foods, other drinks etc. Probably more like 4 glasses a day. Report
Thanks for the info, I try to drink my 8 cups a day but will be sure I practice moderation. That works with everything, isn't that amazing! Report
I always thought that was a wives' tale. Thanks. Report
I just learned that it is just as important not to drink too much. I always thouth water was good for you no matter how much you drank. Thanks foe enlighting me. Report
I had heard about the problem of overhydration. Gotta luv Dr. Oz!!!! =)

I also had a friend of mine whose daughter went to the dr not feeling well. He told her she was actually drinking TOO MUCH Gatorade. Gatorade is good for u as far as the electrolytes, but u want to use it only during time's when u are working out & need the replace the loss of electrolytes. Drinking Gatorade as your "regular beverage" is not good for your body. On down times when not working out, u want to go with water for hydration instead. Interesting info! Report
WOW! Who knew? Report
Good to remind folks. We hear of the problem now and again, but it is so easy to forget about too much of a good thing ... Report
thanks for the blog! Report
I'd heard of hypernatremia but it's not just a problem for runners and athletes. Drinking enough is important, but people don't seem to realize that varies from person to person and situation to situation. Even eight glasses a day might be too much for some and it can really hurt a child. Report
Good information! Drinking water has always been a struggle for me. I am not going to fight with myself in the future. I'm also going to look into taking in more electrolytes. Report
Wow. I love it when I learn new things from an SP blog. This was definitely new to me. Report
I'm no marathon runner, but I have gotten overhydrated in even 35-minute slow runs & in extended hikes in tropical heat. My main symptom is dizziness, plus tingling in my fingertips. Eating something salty--saltine crackers or a salty fried plantain--takes care of it for me. Maybe I'm especially susceptible because my normal blood pressure is already on the low side--? Report
I have heard of this in all exericisers, not just runners. But being able to tell is the hard part. Report
Wow, this is very interesting! I don't drink enough water, so my goal has been to drink at least 4cups a day.... I also do not run but I do speed walk, which is great. Great information though. Report
Thanks, Nancy! Great blog and potentially life-saving information! This was pretty much what you and I talked about Saturday night after the convention. I have never measured my sweat rate--I know that I should have--but I am going to do so on my next run day. Report
Very interesting and surprising Report
thanks much for the blog...I wondered why I was feeling bloated....with no sign of any other digestive issues from my PCP's testing. Despite my Specialist's warning me to stay at 8 cups of water intake, I was drinking 10-12 cups assuming it was good for me! Ever since I came to SP, everyone has been pushing water on members....however, I am on large doses of diuretics...finally my doctors even said " I am emptying the tank with a diuretic while you are re-filling it!!" Ever since I brought the water down to 8-9 cups since a couple of days now, bloating has left...thank heavens. Now I understand what was happening...4 cups of decaffienated tea plus 12 cups of water could do it!!!! Report
I have more than once not consumed enough fluids but I do not know of a time that I over consumed water. I am doing better and better and staying hydrated. Thanks for the warning about over consumption of fluids. I will definitely keep this in mind when I participate in lengthy athletic activities. Report
I can attest to what flushing your electrolytes by drinking too much water can do. I've never drank to the point of water intoxication, but I did drank to the point of causing a very severe cramp in my calf back in August, which I am still dealing with today! Over hydration can lead to injury for runners. Report
I knew about overhydration, but I did not think about it happening to runners. I clicked on the link in this article for how to measure, and it appeared confusing. Some of the acronyms I did not understand either in this article. I don't drink enough water personally. Report
I knew that if there was such a thing as dehydration then there should be something as over hydration I just never imagined it was this common or knew of the symptoms - Thank you! Report
Have you heard of overhydration or water intoxication? No, I hadn't!

Were you aware of the dangers drinking too water much can cause? I knew it was pretty hard to overhydrate, but now I see how it could happen. Thanks for the info!

Are you surprised that this issue is not more on the forefront? No, because I think it's more likely that people are not hydrated enough, than overhydrated. Still, a good issue to be aware of. Thanks again! Report
Good to know, thank you for the heads up :) Report
I was very supprised!!!! Report
When I first joined SparkPeople, there was a lot of talk about drinking too much water; so, for my web search, I did some checking and came across several articles on hyponatremia.

Kat Report
I never knew athletes had a problem with this. I assumed all the water sweated out would need to be replaced by more water, and never thought about it being dangerous. Good to know. Report
I am well aware of over hydration/water intoxication professionally as I am a Registered Nurse & more so personally. I turned forty years young in 06/1994. At that time I started to slowly put on 85 pounds over the course of about eight years. I was able to loose 75 pounds in a shorter period of time, I was younger & healthier then. To help myself do this I had started to drink water apparently more than I realized but was informed by friends & co-workers about the high quantity of water I did consume daily. On July 5, 2005, I sat on the edge of my bed as I needed to get up & ready for work. I looked down at my feet & couldn't believe what I saw, or didn't see depending on one's perspective. My ankles were gone & my lower legs & feet were swollen beyond belief. To make a long story short, what I had done by drinking so much water was I put myself in water intoxication. My vascular system/blood circuitry & my heart were proven to be OK, as per a Vascular Surgeon & my Cardiologist, however, my lower legs & feet especially, but also the rest of my body as I had gained 20 pounds in only 1 month's time, remained drastically swollen. My cardiologist did alot of blood tests which proved that I was indeed in water intoxication. The main result was, from drinking so much water, my sodium level in my blood was way to low, I had what is known as hyponatremeia. When I went to see my internist I was in luck as he also specializes in kidney disorders. He had further tests done which showed I had Syndrome of Inappropriate Anti-Diuretic Hormone secretion or SIADH, it's acronym. ADH helps your kidneys in the excretion of water in your urine based on the amount of sodium your kidneys sense passing through. If I remember correctly, several years ago as part of initiation a group of young men were forced to ingest copious amounts of fluid in a relatively short period of time. Subsequently some of the boys seized & died since the seizures were not treated soon enough. They seized due to their sodium levels being to low as a result of ingesting the copious amount of fluids in the extremely short period of time in relation to the large quantity of fluids. Fortunately for me my doctor restricted my fluid intake for awhile until my sodium level in my blood was closer to normal. I don't know what the rule is on how much one is to drink in a day. The water restriction I was put on included everything, IE - did I drink any after brushing my teeth, my A.M. beverage, what I had to drink w/ lunch & dinner. It was not an easy thing for me to do, however, if I wanted ankles & to loose that 20 pounds, I think you know what I decided to do. There have even been some medications I was given that caused my lower legs & feet to swell. I think we each have to find the happy medium that works best for us individually & replenish any fluid we may have lost in a short period of time. Personally & professionally I do not think there is a steadfast rule that will work well for all. We each need to find our own rule to follow in order for our bodies to remain well-hydrated. I thank-you for reading this, I can get verbose at times, & may you all have a pleasant day. : ) Report
I have heard of water intoxication from an article about a lady who died from it because she drank too much water to win a contest, but that was from drinking WAY to much. I wouldn't have know that over drinking would do these things. It is great to have people share their experiences and knowledge to help us fellow Sparkers who are new to these things. Thanks. Report
I am aware of this issue, and have been for a number of years.

By the way, you might want to edit the first sentence. You want to use "soar" not "sore". Report
Another arena for 'moderation in all things'--who'd have thunk it? Report
This knowledge is very new to me and I would not have even thought this would be the case. I, too, would assume to drink, drink, drink. Now, I am aware of the dire situations that can occur. Thank you! Report
Wow!! Who knew too much of a good thing (water) could be bad for you. Thank you for the info!!! Report
This is important stuff. My 75 year old mother who is an avid walker and gardener just spent 7 days in the hospital for this. We thought she had had a stroke, based on her actions,and instead learned she had just drank too much water. That coupled with the heat of the summer her sodium count finally fell below the normal level and she was in crisis. Normal sodium 130-145. She was 111 and it took a week of hospitalization to get her back in normal range. She had always heard drink plenty of water and when she worked outside or exercised she ramped that up. We live in Texas so the heat intensified the problem but she is not a marathon runner or super athlete so be carefull out there. Report
I have been told to weigh myself, divide that number in half and that is how many ounces of water I should drink each day. Is that correct or is that too much water, especially if I am overweight? Report
I have heard of water intoxication. I have heard of a death of a woman who tried to drink 2 gallons of water. Report
Yes, I have heard of it. The people who run charity events (walks, runs) probably have the most experience with it, because they attract a lot of non-athletes to participate in a strenuous event for a good cause. During the 2000 Washington, D.C. Avon Breast Cancer 3-day (which I participated in) several women had to be hospitalized for it. I heard about it later from one of my doctors. He heard about it through his medical contacts; I doubt the sponsors of the walk wanted it publicized. I believe the event has been shortened since then. Report
I had heard of overhydration. My father used to drink a gallon of water a day. He thought, if one is good, two is better, until his doctor told him he was in danger of washing the electrolytes out of his system (and my father is not overly active.) That's when I first realized, everything in moderation. The trick is, learning what the moderation point is. One line of cocaine is too much. Two gallons of water is too much. But two bananas a day? Perhaps, just right. Report
Some of the race directors are putting information about this in the race packets of marathons and halfs and that is a good thing. But as a running coach, I hesitate to discuss this with my novice runners training for a 10k. In my experience more people under hydrate than over. I have a friend that is very experienced and has been hospitalized 3 times w/ heat cramps, Boston Marathon, Chicago Marathon and at a recent long distance biking event. I was with her at the biking event and am embarrassed to say I didn't recognize the signs, nor did she. I am a heavy sweater and was sweating and drinking much more than her. It was an extremely hot, humid, and windy day. I picked her up at the hospital and after she had stayed about 6 hours and was given several bags of fluid she still looked and felt horrible and it was over a week before the muscle soreness from the cramping went away and she felt like herself again. She could have easily died and this was a life changing experience for her. I am in no way minimizing the importance of long distance athletes being aware of the possibility of over-hydration and taking appropriate precautions. Hyponatremia is serious and often deadly. Pay attention to your body and hydrate accordingly. Report
I have an obsessive-compulsive disorder called polydipsia, in which I crave water. I was drinking 22-24 8-ounce glasses of water per day. My blood pressure was up, and I felt weak and tired, had muscle cramps, etc. My psychiatrist and internist diagnosed the disorder after ruling out diabetes; that OCD runs in my family helped with the diagnosis. I am now limited to no more than 10 glasses of water per day, preferably eight. I have had to learn to sip water rather than gulp it. I found laboratory wash bottles that are squeezable and have a long nozzle tip are ideal for aerobics and other exercise. One squeeze will last quite a while. I am now so attuned to my body's needs, that I can tell when I actually need water and when I should cut back. Report