Micturation data

October 21, 2013 • 10:11 am

I recently wrote about an upcoming paper on the duration of urination in mammals, in which physicists argued that there is a New Law of Nature: all mammals, regardless of size or lifestyle, tend to urinate for about 21 (± 13) seconds. That was based on empirical observation and then explained by principles of physics and hydrodynamics that have not yet been clarified, as the paper hasn’t appeared.

But experimentalists are skeptical, so this mammal decided to test the theory himself. I won’t bore you (or gross you out) with the experimental details, save to say that it involved a series of ten timed “episodes.”  And here is the statistical analysis of data (in seconds) from yours truly:

Micturation StatsI’d say that fits the theory nicely. The standard error of the mean is quite small: 0.86 seconds.

Readers are welcome to provide their own statistics, but try to urinate under normal conditions, i.e., not after a long night in the pub.

74 thoughts on “Micturation data”

  2. It certainly doesn’t seem to be borne out by Frank Drebin in “The Naked Gun”. Search for “press conference pee scene” on YouTube if you’ve not already seen it.

  3. Your prostate probably is not yet enlarged. Wait till you’re 80 and watch out for the “geriatric dribble”.

    1. If you are afflicted with prostatic enlargement that impedes the urine stream, it’s very important to make sure you completely empty your bladder. When you think you’ve finished, wait another 30 seconds or so and you’re likely to put out another 5-10 ml. Not much, but failure to completely empty the bladder is a major causative factor in the development of bladder infections. And that tiny amount of urine is sufficient.

  5. My dataset isn’t as large but it seems to corroborate. You know it’s bad when you go to pee and think, “I should be timing this – damn, I forgot!”. 🙂

    1. Bill Cosby had a short monologue on this — in which he expressed his admiration for the female ability to choke off the stream when peeing in the open and being told “someone’s coming.”

  7. Does this include animals that mark out territory through urination? I’d have thought that would be quicker.

      1. Again – gender — male dogs attempt to pee on anything taller than a pebble — even when they have exhausted their supply of urine. Female dogs pee once, until finished, and then simply sniff the “news” left by other dogs. Which is once of the reasons I have only ever had females — I do not want to have to stop at every tall weed!

        1. Oddly, not all male dogs are like that. My big male ‘mountain cur’ (a breed not generally well known, and not for everyone) pees just once on our walks, and does it like a female. He never lifts his leg.
          Wonder if that comes from being well neutered.

          4. Diana’s suspicion is the same as mine, based on an N of 1 – it’s a learned behavior. My trusty Beagle-y hound (Beagle / Brittany Spaniel mix) Madison didn’t start peeing by lifting his leg until well past 10y/o, and only after spending some time with another male dog.

          6. I had never heard of this breed before. We found him at an animal shelter as a part of an abandoned litter of the cute, scrawny puppies. We thought they were greyhounds or greyhound mixes since they sure looked like them. Percy is now a big, strong brindle-coated speed demon with a greyhound body and a hound dog head. And he wants to work, as your excursion might tell you about this breed. Quite a handful, but I love this clown more than any dog I ever had.

          7. I love the brindle colour! My parents used to breed labradors and our dog got knocked up by a random dog because they didn’t realize she was in heat or something….anyway the resulting puppies were the cutest brindle things!

            The temperment of Percy sounds like my dog Kala who is high energy. I rescued her as well (through a rescue group that takes animals from high kill shelters). She was on death row in Ohio. Since she is so tall and thin, I thought she had to have dane in her or something but I had her tested & she is 100% lab. So, I think she was probably a dog with field trial ancestors as those dogs are typically intelligent, high strung and not always bred to exactly meet the lab standards since performance is valued over appearance.

          8. And my female shepherd mix pees like a boy, though doesn’t lift her leg quite as high. I guess she’s kind of an alpha female. She also pees almost as often as a male when we’re out hiking.

        1. Thanks, Diana. LOL I am chuckling at the thought. I expect she is sniffing all the while, collecting “news” left by other dogs & passersby.

          1. It’s weird, I think she is just too busy to be bothered taking a proper pee break! 🙂

  8. I expect that those investigators made the same mistake you have. They had a limited — and all male — population. Also, they overlooked such problems as prostatic hypertrophy, which leads to prolonged urination, with a very thin stream. For women the problem is stress incontinence and/or urge incontinence. Bad science to overlook the parameters of gender and age and medical history. You may have intended this post to be humorous. In fact, it provides a teachable moment for scientific method.

    2. Oh please. Yes, it is light-hearted, but neither of us has seen the paper, as the details haven’t been published. So it’s useless to speculate what the authors did. Lighten up and wait for the paper to come out, please. At any rate I have data on myself, and others can compare theirs.

  9. Tendency, okay. But I think its fairly easy to exceeded that maximum — i.e. being trapped in a moving car piloted by a maniacal driver obsessed with making “good time”, not wanting to exit a theatre during a live performance, going to see an exciting film and absent mindedly polishing off a jumbo soda toward the start of the picture, etc.

    Also — 21 (± 13) seconds! Perhaps I am jaded, but given such a huge spread, I don’t think those findings are all that surprising …just sayin’.

  11. Does it include Marine Mammals too? I wonder how one might measure the pee times for whales…I mean without using a completely invasive device that might change the results.

    I never realized mammal urination time is something that might interest me — perhaps this is my “personal growth” achievement for today.

  12. Doesn’t this finding make sense from an evolutionary standpoint? Wouldn’t any species which engaged in more leisurely cleansing of the kidneys have been at a serious disadvantage and suffered negative selection? Micturation is distracting to the micturator and attractive to the predator. Think of that experience as you, sir, stand at a public urinal and someone walks behind you? Chokepoint!

  13. Commentators who refer largely to their own, individual time-limited experiences should recognize that when we are older or have bodies breaking down, we are heading for individual extinction.

  14. What I’d like to know: Why do we have the urge to urinate when we hear the sound of running water?

    1. Everything goes to the main experience of our human ancestors who for 99% of our existence lacked indoor plumbing and stuff, no? So, as anyone knows who goes camping, water is not everywhere. When we hear the sound of running water, we know that fresh water is available and thus can release supplies of water still held in the body to make room for new stuff and for a cleansing of the hydration system…or something. By the way, I’m an English teacher, so I apologize to the scientists for my presumption.

        1. Good point. But it’s all a system. Your bladder is never entirely dry (we can’t completely empty it) but it can’t be healthy to have a small amount of highly concentrated poison in there (Ever look at your orange pee on a hot, hot day?)so the sound of running water, water we are going to dip into and fill our bellies with, stimulates a desire to let go at the other end. Some people don’t like to drink. My mother was dehydrated her entire life because she didn’t enjoy drinking water or anything else. I LOVE to drink cold unsweetened water or tea and I’m never de-hydrated. I’m water-logged.

        2. You can suck water back out of your bladder if you start to dehydrate, that’s one reason your urine gets darker if you don’t drink enough.

          1. I doubt that very much. Rather, the tribe gets darker because your kidneys filter less water from the blood, resulting in less water in the urine.

          2. Indeed you are correct. I have “known” this for decades and I have no idea where I “learnt” it but it certainly doesn’t seem to be right. Yet another example of shitty design, it would make sense to be able to do this but we can’t.

          3. No, this doesn’t happen. It would occasion kidney infection. What happens is that your kidneys concentrate the urine – or they should. If they don’t then you are probably in kidney failure, which is very bad news indeed.

          4. Concentration usually involves decreasing the H2O volume, no? Where does it go?

            (Not doubting, just curious.)

    2. I’d guess it has something to do with running water sounding like someone else urinating. The human ability to ‘experience’ someone else’s sensations might accidentally trigger our own need to urinate?

      1. As a Rehab R.N. I am accustomed to using running water (from the faucet) to help stroke victims recover the ability to urinate at will. I suspect that many mothers use the sound of running water to similarly stimulate their children to urinate when in a strange bathroom (which inhibits some people from doing so).

        1. I just like the idea of having “white noise” so that the sound I make urinating isn’t that obvious. Come to think of it, it would probably be adaptive to make as little new noise as possible. OTOH, prehistoric people using the bush probably wouldn’t have made much noise in the first place…

          Still, it might be a result of it being desirable to attract the least amount of attention while one is temporarily preoccupied.

        2. From one R.N. to another: and post-op patients who can’t pee because the anesthesia hasn’t completely worn off.

  15. ALL mammals, regardless of size? Hmmm, I don’t know…ISTM that for a prey animal to spend 21 seconds either standing still or laying down a scent trail would not be a successful trait to pass to the next generation. My father raised rabbits in the backyard for a number of years, and while I never timed them, I’d say a typical session was more like 3 to 5 seconds.

      1. Race horses don’t pee any differently than do other horses. It’s just that few of us ever see any horses in realistic situations, ie. peeing. The track is a rare exception. Also, many of the males at the track are stallions and thus put on a show when they “bleed the rat.” Sorry, I need to go for a walk and clear my sinuses.

        1. That’s okay. I’ll still use the hyperbole even though it’s not really a hyperbole because most people will be ignorant of this research….or of course I can also ruin it for everyone else.

          1. I’m not timing myself but I think I will time the horses (all mares though) – I was thinking of the ‘pee like a race horse’ expression as I was idly watching all 3 take a pee within 3 minutes of each other the other day (things to do on a lazy Sunday) – it’s an impressive flood but it doesn’t go on too long. Easily within the predicted range I would have thought.

          3. Yeah and probably what the original expression refers to since it is sure a flood when a horse goes pee.

        2. Most racehorses don’t pee differently than other horses. However, many racehorses are on diuretic medication, particularly Lasix, because diuretics prevent racehorses from bleeding from their noses and in their lungs. Diuretics will cause the horse to pee more often and longer than other horses. Perhaps this is why the saying got started.
          http://www.horsefund.org/the-chemical-horse-part-8.php

          1. As in other elite athletes, diuretics probably mask some of the other performance-enhancing medications they’re likely to be using…

  17. My data st is sloppy in that I haven’t written anything down. But I have timed myself about a dozen times in the last few days. I never got above 19. I was as short as 7. Mostly in the 13 to 16 range.

    I’m in my young fifties. It has been my impression over my entire life that I have to “go” more frequently than most people around me. Whenever I’m in a group setting — say a men’s room in a busy interstate rest area — I can arrive after and leave before the men nearby.

    All I can say is that if I had to be below average in some way, urinating ability is fine by me

    1. My all time high was 30 seconds. I do tend to hold it longer than I should because I am busy working on something so maybe I saved it up too long. Still 30 seconds – pretty awesome!

      1. Isn’t that funny? My longest (first thing in the morning) took 30 secs. My shortest was about 10 secs., despite feeling the urge.

        Do you own a Rottie by any chance, Diana? I asked because, like what you said earlier, our late Rottie used to crouch-walk and pee at the same time. She also used to do multiple squats on her walk, and mark with short squirts.

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