Tight Underwear Prevent Muscle Growth?

Hi Davey,

There are a lot of people that say that tight underwear lowers our sperm count and testosterone levels, thereby preventing muscle gain. Is it true?


Hey Frank,

I’m so glad you asked this question!

First things first, it’s common knowledge that testosterone aids in muscle growth. The more testosterone you have, the more muscle you’re likely to build through your training. And, of course, this has been proven time and time again through the use of anabolic steroids, which - though dangerous - mimic testosterone and result in muscle growth.

If you do a Google search, you’ll see countless websites warning of the link between tight underwear and reduced testosterone and sperm counts. But rarely do they cite any research to back up their claims. I’m interested in science - not rumors.

These rumors note that the testes hang from the body for a reason; they need to be cooler to function properly. By wearing tight underwear, we hold the testes close to the body - thus, potentially raising the internal testicular temperature and decreasing functionality.

Not surprisingly, researchers have studied the link. In fact, back in 1998, Munkelwitz and Gilbert from the University of New York published a study about underwear and fertility titled, “Are Boxer Shorts Really Better?” After studying a number of volunteers, the researchers concluded that there is “no difference in scrotal temperature depending on underwear type” and that it was “unlikely that underwear type has a significant effect on male fertility.” Since testosterone influences sperm count, the research suggests that its levels aren’t influenced by tight underwear. Since then, other studies have come to similar conclusions.

Reduced testosterone levels can be caused by any number of conditions or circumstances, including:

  • Testicular damage
  • Post-puberty mumps
  • Radiation or chemotherapy
  • Testicular tumors
  • HIV/AIDs and other viral infections
  • Genetic conditions

Whether you’re in favor of boxers or briefs, know that it won’t affect your testosterone levels or your ability to build muscle. What you eat and how you work out, on the other hand, will greatly impact your results.

Davey Wavey

About Davey Wavey

Davey Wavey is a certified personal trainer and YouTube sensation with more than 250 million video views. For Davey's fitness tips and secrets, sign up for his free monthly newsletter - or download any of his affordable and effective workout programs.


  1. Besides, tight underwear looks so much better 😀

  2. Thanks for answering questions that are on our minds!

  3. Thanks for your answer Davey!

  4. Vladimir Horvath says:

    oh he definitely forgot about the great combo of boxer briefs lol that way i get two in one you see hahahaha

  5. I just like the guy in the picture. No seriously, wear underwear that makes you feel comfortable and sexy. That alone will boost your testosterone (maybe). 😉

  6. Brian Baldwin says:

    Too loose or too tight to be comfortable? My well endowed partner brags that he can not wear boxers because his stuff gets tangled up. My not so big stuff enjoys a loose fit in order to stretch. Something it does when I spy a guy in fitted underwear.

    • But it’s true! Hanging out of the bottom of your boxers in a public setting where it would not be considered socially acceptable to adjust yourself is no fun. Then, by the end of the day, you’re all chaffed and whatnot. Boxer briefs and the occasional sexy jock strap are totally the way to go. I only have boxers lying around in my drawer for when I’m doing my laundry and it’s too chilly to go commando haha 😉

  7. This totally should have been a talky blog with visual examples and close ups 😛

  8. Have to say the undies on the guy in the pic are not tight, infact they look pretty loose…

    also totally agree with Kyle’s comment…

  9. The question is absurd, but the guy in the pic is beautiful.

  10. phew, I’ve been always worried about this because I’ve wore tight underwear for a long time before hearing the rumor. Thanks so much for the confirmation.

  11. I wear thong but my balls hang out and some times my c*ck , If it loss .
    tight keep it in me .
    But after work it feel good take them off and wear nothing under your pants .
    Yes boxers feel good in bed as long sexy looking , Boxer briefs are sexy to not as briefs low reise breifs .
    To me low rise brifs sexer .

    You wear high brifes not low rise brifes .

    Come down to it why wear under wear ?????

  12. I love that sexy body … and takes away from this serious ….

  13. Cold showers increase your testosterone level so you can try that method. It can help.

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  16. I enjoy wearing tight underwear when working out. It keep everything in its place and you never know who is watching…Then in the changing room when you undress and out flops your monster then it make sit all worthwhile.