Boxers or Briefs?

Boxers or Briefs?Believe it or not, it’s a question I get fairly often: “Grok didn’t wear tighty-whities. Should I?”

From time to time, I like to have some fun and expand the scope of this blog beyond the regular topics. Health and wellness, after all, come down to far more than just diet and exercise (and sleep and sun and stress, for that matter). So I’ve written about everything from the benefits of squat toiletsgoing poo-less, and stand-up workstations to the dangers of excessive sitting, nighttime light exposure, and passive living. Today, I’m going to branch out again. Today, I’ll attempt to answer what sages, wise men, gurus, and guys sitting around in gym locker rooms could not: boxers or briefs (or nothing at all)? So fill your cup and let’s dig in.

This topic was prompted by a reader’s email:

I thought this could be an entertaining topic.

We’ve all seen the Seinfeld episode where Kramer starts wearing boxers when Elaine tells him boxers are better for his sperm count.

Is there any hormonal drawbacks associated with briefs that could be caused by the low sperm count or vice versa?

Our ancestors were certainly “out there, and loving every minute of it.”


Here’s the Seinfeld clip in question:

Having watched that, I’m not even sure a post is necessary. Kramer pretty much covers it. Still, not everyone has access to YouTube at work, so I’ll continue.

I’m not going to discuss the subjective effects of wearing boxers, briefs, or nothing at all. People have their preferences. Some people like providing a safe, secure, snug house for their boys, while others take a more free-range approach. No value judgements cast here.

But what’s our natural state?

While it could be argued that going commando is “most natural,” seeing as how we’re all born in the Hanes-less state, I’d say that loose-fitting boxers are pretty close to natural, too. Loincloths were the earliest undergarments, and those were essentially just a piece of fabric loosely looped between the legs. Plenty of air flow and very little confinement. Grok’s private bits definitely breathed, whether he wore a loincloth or nothing. Okay, so one is more natural than the other(s), but does that make a difference for our health? Natural doesn’t always mean better, you know.

“Everyone knows” that wearing tight briefs reduces sperm count, and I briefly discussed this in a Dear Mark that asked about laptops and infertility. It’s true that scrotal heat stress does have the potential to affect sperm quality, count, and motility, as in men with varioceles – enlarged testicular veins that lead to excessive blood flow, elevated scrotal temperatures, and sometimes infertility – but it’s unclear whether choice of underwear represents a significant-enough thermal stress to the scrotum to induce negative changes. The questions we must ask are: does the choice of underwear truly affect scrotal temperatures? And if it does, is it sufficient to negatively affect male fertility? Let’s look at the evidence:

In one study, healthy young men wearing tight-fitting polyester-lined athletic support garments consistently displayed elevated scrotal temperatures between 0.8 and 1 degree C. This increase, however, did not affect any fertility parameters, including sperm concentration, sperm motility, sperm morphology, sperm viability, sperm hyperactivation, and the ability of sperm to penetrate hamster oocytes (sadly, no hamster-human hybrids were created throughout the course of this study).

Another study found no difference in scrotal temperatures between wearers of boxers and wears of briefs. In fact, the average temperature was actually a hair lower in the brief group, though it wasn’t significant. Fertility parameters all checked out, as well.

In another study, the author measured how various garments and positions affected his own scrotal temperature. Boxers were 0.5 degrees C cooler than briefs. Scrotal slit underpants were 1.2 degrees cooler than boxers. Sitting with thighs apart was 1.6 degrees cooler than sitting with thighs together. He didn’t measure his fertility parameters, however, so we don’t know whether or not those were affected.

And finally, a team of researchers studied the effects of boxers, briefs, and going commando on the scrotal temperatures of 50 healthy men without a history of infertility. They found conclusive evidence that wearing tight-fitting underwear such as briefs resulted in elevated scrotal temperatures, though it “remains to be elucidated whether these differences are linked to semen quality and consequently male fertility.”

Choice of fabric might make a difference, too. In an Egyptian study, one researcher used polyester slings (that allowed penis exposure but kept the scrotum confined) to induce azoospermia – the state of having no measurable sperm in semen – in previously fertile men. These were like briefs on steroids, fully preventing the tendency of the scrotum to “hang low” (which it does for thermoregulatory purposes). They caused the testicular temperatures to approach the rectal temperatures, which is way hotter than testicles are built to withstand and which apparently contributed to the infertility. But the author also thought that scrotal-polyester friction-induced electrostatic charges might have played a role as well. To figure out which was responsible, that same researcher did a followup study, this time using dogs in specially-fitted underwear. To eliminate the confounder of scrotal temperature, he made the underwear loose fitting. And sure enough, testicular temperature didn’t change much. Not even in the polyester group. The dogs wore the underwear for 12 months straight. Once again, the polyester underpants killed fertility (without affecting temperature), while cotton underwear dogs and control dogs (commando) experienced no change. I was alive during the seventies, and I can certainly vouch for the friction that occurs between bare skin and polyester.

As for the hormonal stuff? While scrotal temperature changes do affect follicle stimulating hormone, which controls sperm quality and count, they do not seem to affect testosterone levels. Fertility can be affected, but not via testosterone.

I wish I could give you an absolute proclamation, here, but I can’t. How about some general guidance?

  • If you’re having trouble conceiving, or your sperm count comes back low, and you wear briefs or some other tight-fitting underwear, switching to boxers, or cotton, or nothing at all might help. Either way, it’s not going to hurt.
  • Normal scrotal temperature – the kind that promotes fertility – is one or two degrees C below body temperature. As seen in the Egyptian study, once the scrotal temperature approached the rectal (body) temperature, fertility was impaired. The best way to measure your scrotal temperature is with an infrared thermometer, which can be a bit pricey.
  • Don’t wear tight fitting underwear – polyester or not – for 12 months straight. Give your boys some time off, whether that comes through targeted ice baths, walking around (walking and standing and even running lead to cooler scrotums than sitting) more, or switching to more forgiving undergarments.
  • Switch to a natural fabric, whether it’s cotton, animal skin, or nothing.
  • Don’t be in such a rush to always replace your underwear with a gaping hole in the crotch. It might actually be helping, especially if it facilitates scrotal drooping.

Thus, as is usually the case, there’s no right or wrong answer here. While wearing tight-fitting briefs can increase scrotal temperature, which can affect fertility, it’s not a sure thing. The research is unclear, and the ultimate choice rests in your hands. Go ahead and mess around with infrared thermometers if you’re really concerned, and get your sperm count tested, but you probably don’t have much to worry about as long as you’re adhering to the general guidelines listed above.

So, dear readers, what say you – boxers or briefs?

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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106 thoughts on “Boxers or Briefs?”

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  1. That’s it – my better half is getting a loincloth for Christmas!

  2. What about during workouts? Especially runs and sprints. I was always told to wear tight underwear during runs to prevent things from bouncing around too much and getting damaged.

      1. I use under armor compression shorts when I work out. I find that there is less chaffing than if I wear boxers. If my balls are really tight against my body for an hour or two, will that have a negative impact on fertility?

    1. I’ve always been under the impression during sprints you need to wear tight fitting boxer briefs to avoid testicular twisting where the bloods supply can get cut off. A quick google calls it “testicular tortion”. Seems some other issues may be at play but I’m going to protect the boys during exercise with some boxer briefs.

      1. I knew a guy who had to have surgery to correct that. Quite painful. Not that I have any insight as to the current topic. Just felt like sharing.

  3. Cotton=pesticides Hemp or cotton=no pesticides. I wear hemp boxers although pricey at $38 a pair, best pair of underwear I ever owned. I have two pair and me thinks I need them in all the colors.

  4. I turned my back on underwear several years ago, I let the boys hang loose as nature intended.

  5. I can pretty much guarantee the comment of the week will come from this article. I’d be willing to bet it also uses the phrase “scrotal drooping.”

  6. “What’s worn under the kilt?”
    “Nothing, ma’am, it’s all in perfect working order.”

    1. That’s what this Toad where’s – exefficio boxer briefs. Perfect for traveling 🙂

      1. I totally agree Sir! Exofficio has been a real pleasure to wear 🙂

  7. A greater and more overlooked threat to your swimmies is your cellphone kept in a pants pocket. Grok sure as hell never thought that microwaving his ball sack would be a good idea, neither should you.

    1. luckily its getting cold so my cellphone will be kept in my jacket pocket, so hopefully someone wont be stealing my outdated droid x

    2. So true. I’ve been keeping my cell phone in my backpack more recently to not spend so much time on it. I guess this is a side benefit!

  8. Middle-aged comedians joke about their sagging ballsacks. How they have to move them to sit. How the dangling mess is always in the way. Like a bra, tighty whities support that thin skin so you aren’t a sagging mess later in life. Your decision but plan for your future.

    1. It is my understanding that it is a myth that bras prevent breasts from sagging.

      1. It is totally a myth about bras preventing anything except fun.

        1. Actually, Bras prevent breast ligaments from over stretching. While they might not eliminate all possibility of saggy boobs, a proper fitting bra will definitely help prevent breasts from sagging (ask my 92 year old grandmother, haha).

      2. It is a myth indeed, as far as I can tell. While bras do prevent the ligaments from stretching, they also prevent the ligaments from doing their job of holding up a breast. So, they get weak and it leads to sag anyway. Those puppies are going to sag if they want to no matter what we do. Non-sagging seems to be completely out of our control.

      3. Without embarrassing my little mum, she’s still pert at 81, and I’m in the footsteps at 47. Of course, micro-bosoms are gravity-agnostic to start with…

    2. It’s my understanding, thin skin is a result of natural aging, and cannot be prevented by garmentry.

      In other words, skin continues to lose it’s bouyancy with age. Nothing will ever prevent the droop bar surgery.

  9. Totally anecdotal, but… my husband has always required a snug home for his boys, and we’ve got four kids…

    1. serves me right for reading the comments… did not need to know, mom!! 😀

  10. At my age, I could honestly care less about fertility 🙂 but…I still go commando. an old habit from the military that I have yet to experience any desire to break.

    I also run and work out with the same. throw on the sweats and go. I have never experienced any issues with soreness or anything else even in full sprints. only time i get sore is when im getting kicked there :)But, that’s what cups are for.

    1. I’ve actually had better results with Merino Wool than Exefficio.

      I recommend Smartwool underwear, and Icebreaker shirts.

      It’s INCREDIBLY comfortable, organic, AND flame resistant.

  11. equal time between boxer-briefs and just boxers. Gave up the tighty whities in college. They just felt embarrassing to wear.

    1. it took you til college to realize tighty whities weren’t cool…?

  12. My father’s 93, a boxer fan all his life, he’s hanging down around his knees. I think you got to mix it up, if you hearing “Born Free” when you wake up go Commando! I’m just sayin……..

  13. After my third child was born (and I always wore tighty whities then) I had a vasectomy (so long ago the doctor used a stone knife). So the sperm issue became a non-issue and my wife and I had a lot more spontaneous fun. Then, in my 30’s I went commando, in my 40’s, boxers, and in my late 50’s I switched to boxer briefs, which suit me just fine.

    1. Forgot to mention: When my children were born I was living in Arizona (Mesa, Phoenix area) and working outside doing construction work in the sometimes incredible heat. So I know my boys got really hot most summer days.

  14. We live in Florida, and my fiance used to love his boxer briefs. Loved the support, he said. They got so worn out that I bought him a new pack about a year and a half ago, but the same size was so incredibly tight and uncomfortable (evidently the old ones were REALLY worn out) that he started letting it all hang free. He says it’s much, much cooler during the summer now, far fewer incidents of sweaty man parts. Never having had sweaty man parts myself, I can only assume it isn’t pleasant. Here’s to being naked under our clothes.

  15. This confirms my choice to go commando about 70% of the time. And yes, I gotta hook up a kilt soon.

  16. “I was alive during the seventies, and I can certainly vouch for the friction that occurs between bare skin and polyester.”

    L – O – L!

  17. “What’s worn under the kilt?”
    “Nothing, ma’am, it’s all in perfect working order.””

    If you wear anything under it, it is a skirt

    1. I wear robes, you know like hefty robes that Greek scholars or Shogun use to wear. Amazing!

        1. Traditionally? No. The English decided to tell the Scots what Scottish fashion and heritage was a couple centuries ago (in an attempt to make them more loyal or something). Prior to that all Scots were barefoot at all times, including winter, and including even the highest nobles.

  18. Do your balls hang low, do they waggle too and fro~

    Sorry, couldn’t resist. XD

      1. Would you like them
        in a house?
        Would you like them
        with a mouse?

        In the dark?
        Here in the dark!
        Would you, could you, in the dark?

        Would you, could you,
        in the rain?

        Could you, would you,
        with a goat? Er, forget that.

        Would you? Could you?
        in a car?
        Eat them! Eat them!
        Here they are!

  19. I’m a big fan of ScottEVest “Travel Boxers 2.0”, with not one, but *two* pockets in them, and a button to close the fly for those modest times, and dry-fast fabric to wash in the sink while you’re on the road a lot (like me).

  20. I love men’s boxers (for me) for sleeping.

    I have a stack of 2(x)its brand, size small, plain white. So soft. They’re perfect with a long sleeved white tee shirt (I have a stack of those too, from places I’ve traveled).

    The perfect jammies. 🙂

      1. Way to be a creep, dude. How can you think for just one second this is appropriate behavior?

  21. I was a young teen in the 90’s when it was fashionable for females to wear men’s boxers under their overalls, and even jeans. I remember not liking to go with that trend too often becuase it was really uncomfortable having all that extra fabric from ther boxers. I’m not sure how that’s comfortable for you men. I am not male, but enjoy going commando a lot of the time. It just feels most natural, even as a woman.

  22. I think this is my favorite article — and comments section — yet XD

  23. Well, I’m good my clothes(At home!) Are robes, yes, many robes, and sometimes a loin cloth, or quality boxers. Very, very comfortable. Warning: Do not go commando while wearing jeans! You can guess why.

  24. Sorry, can’t wear boxers because I get hard easily, even when the wind blows…

    But I’m thinking about putting in shoe eyelets in my undies!

  25. wow I swear I was just thinking about searching this topic on MDA today. recently I switched to briefs for comfort and flexibility during workouts. I don’t really like em the rest of the time though.

  26. Tomorrow on MDA: thongs vs bikinis!

    my primal hubby has been going commando since we started dating 23 years ago.. our 5-year old son refuses to wear underwear too.. like father, like son

  27. Lightweight cotton or something moisture wicking for the underwear — and try looser fitting pants instead of all the silly skinny jeans styles.
    Tropical weight wool trousers for hot weather instead of blue jeans. Wool can be incredibly fine and much better for temperature control.

    And I like the switching-it-up ideas. Briefs for activity, boxers to sleep.

  28. Obesity inhibits cooling in the pampiniform plexus (testes radiators), and thus inhibits testosterone production AND sperm motility. Tight undies do the same thing.

  29. Wow! I’ve laughed out loud at several points on today’s topic. Thanks everyone!

    I’m also reminded of an episode of Friends (Season 3) where Phoebe’s new boyfriend wears shorts all the time . . . and goes commando under them.

    1. “This is a family place, mister. Keep the mouse in the house.”

  30. Whoa there, boys! Did someone just come up with non-hormonal and non-invasive male birth control … underwear? Yay!!

  31. Congrats Mark on having the balls to tackle this hot topic. I was inspired by the comments of women wearing men’s underwear to bed, so tonight I am going to try some of my wife’s. Hum, panties, thong or crotchless? I am feeling free.

  32. I am so going to go around all day looking for opportunities to use the phrase “scrotal drooping”

  33. I’ve worn tight-fitting briefs all my life. When it came time for us to have children, the first of which came when I was 37, all I pretty much had to do was sneeze next to my wife when she was ovulating and she got pregnant, first try.

    Did this issue of infertility come about with tight briefs? Heck no. It came about with the increasing use of soy in our diets, along with other estrogenic influences in our lives, not to mention the complete chemicallization of our lives.

  34. A lady at a church meeting was asking me for details on my Primal weight loss. We were interrupted before I could give her the marksdailyapple web address. This would have been the first entry that she read! She’s over 60 and very prim and proper. Imagining her response is almost as funny as that Seinfeld clip.

  35. I wear athletic polyester compression shorts. I got this from when I used to go hiking a lot. Cotton soaks up water and doesn’t dry or breathe as well as polyester.

  36. Having spent the better part of the summer in Afghanistan, I am sold on merino wool undergarments.

    Boxerbriefs, undershirt and socks are all merino wool. It’s pricey, but holy hell is it comfortable, breathable, non-chafing, odor resistant, and flame resistant.

    I highly recommend checking out Smartwool or Icebreaker.

    1. Hi there,
      I do promotion for wool in South Africa and was send your comment by a friend. Would love to know more about your wool experience and send it out on a newsletter, if you are keen?

      Nothing like wool against the skin, but people do not believe it until they experience it…

      Kind regards
      Dalena White

  37. I’ve gone commando for several years now and never regretted it for a minute. I do lots of running, hill sprints, and pretty much every conceivable (functional) exercise in the gym. Never had a problem. I was a bit worried the first time I did lunges and hand stand push ups with nothing but a loose fitting pair of gym shorts between me and a count of misdemeanor public exposure. Never had an issue with that or with any kind of bruising or chafing, which used to be a huge problem for me.

    I highly recommend giving it a whirl.

  38. I recommend accustoming yourself to variety. My husband absolutely refused ever to wear anything but boxers. When his illness started to result in occasional bowel incontinence, the mess was awful. I finally asked advice from other men (on Facebook!) and insisted he try boxer briefs, which he decided were ok. Except he had an issue with the fly being too hard to use, so I had to cut one layer of fabric. I discovered that today the big divide isn’t between boxers or briefs but between men who use the fly (leaving the button and belt fastened) and those who don’t.

  39. As a female, I have to object to this statement:

    “Don’t be in such a rush to always replace your underwear with a gaping hole in the crotch. It might actually be helping, especially if it facilitates scrotal drooping.”

    I guarantee this will not help your chances of procreation.

  40. I have never liked wearing any underwear as early as I can remember,because I have always found them uncomfortable. They always tended to bunch up, get stuck up my ass crack or cause me to sweat too much. Through the years, I have tried just about every kind of undergarment from time to time, and I still prefer to go commando. So, I have been 100% commando for about 20 years.

  41. As a child I used to wear briefs then I switched to boxers when I was 13 or 14. In college I started to wear boxer-briefs. Now I’m switching back to briefs. I feel more comfortable wearing tight underwear

  42. For the last sixteen years I have been a tour operator.As such, I drive considerable distances, and often in warm to hot areas.About fourteen years ago I started to develop heat rashes in the groin area.At the tine I was being by a dermatologist for another problem.I mentioned my heat rashes to her,(yes a lady doctor).The doctor told me that my problem was common, particularly with those who spent much time driving in warm to hot areas.
    Her words to me were:’Allow as much air circulation as possible in the groin area’.When I next visited her, she asked about the heat rashes (She is a relatively youngish lady with a good sense of humour), I told her they were gone.She then asked if I had followed her advice completely to which I replied ‘Yes’.
    That my story with underpants.Incidentally I am meticulous about hygiene

  43. Boxer briefs–my boys need a house, but a roomy, well-ventilated house. 🙂

  44. The only time I wear something tight is when I go running. My doc suggested I use a jock strap after I had a bout with epididymitis years ago, and I never went back. Things are good down there now. I also have been using a penis health creme that contains Vitamins B5, C and D. All of these vitamins are awesome for blood circulation and penis health in particular. You guys should look into it. Cheers.

  45. Underwear is something that most of us buy new. It’s something that I buy new. 90% of my wardrobe is second-hand, and I try to make sure that those things I do buy new are as sustainable and ethical as possible.