Why People Get Gym Nipples? (And what to do about it?)

You wanna know the biggest elephant in the room in most fitness clubs? Gym nipples. Everyone sees them but nobody talks about them.

In my gym I see people walking around with hard nipples showing through their T-shirts or sports bras almost all the time (which is one of the most awkward moments, especially for ladies). Surprisingly, it is not uncommon when girls get hard nipples when they exercise.

Today I will explain why girls and guys get hard nipples when they exercise, and most importantly, what can you do about it.

In general, gym nipples are the term used for nipple stimulation that happens during exercise. People get hard nipples in the gym because nipple erection is mediated by sympathetic nervous system response, increased heart rate, and enhance nitric oxide production.

photo of gym nipples

Why Do My Nipples Get So Hard At The Gym?

You wanna know why nipples get hard in the gym? Let’s talk about human anatomy and physiology.

One of the reasons why people get nipple erections in the gym is due to the increase in the sympathetic nervous system.

In case you’ve missed the biochemistry seminar, the sympathetic nervous system (also called fight or flight response) is part of your autonomic nervous system that helps to control most of the body processes, automatically.

For example, your body digest breakfast on its own, maintains body temperature on its own, and gets goosebumps when it’s cold also on its own.

When you’re about to hit the gym or attend your favorite high-intensity bootcamp class, your body also uses the sympathetic nervous system to help you meet the metabolic demands of your workout.

Does exercise make your nipples hard?

Overall, exercise in the form of endurance training or high-intensity interval training does make your nipples hard.

During exercise, the body increases the fight or flight response. Elevated sympathetic activity increases smooth muscle relaxation around the nipple-areola complex, which leads to nipple erection.

“It has been stated that nipple erection occurs via activation of the sympathetic nervous system and smooth muscle contraction,” says Murat Tezer, Ph.D., a professor from the Istanbul Faculty of Medicine at Istanbul University.

The Science of Why Nipples Get Hard In The Gym

Getting hard nipples in the gym may have nothing to do with sexual arousal.

Nipple-areola complex (the area surrounding the nipple) includes several smooth muscles.

“The presence of abundant amounts of smooth muscles inside the structure suggests that the contraction of these smooth muscles contributes to nipple erection,” explains Dr. Tezer.

Another reason why nipples harden when working out is that nipples are vulnerable to touch via friction. During exercise, there is direct contact between the anterior chest wall and the clothing.

Frequent touching and chafing of the nipples during physical activity can lead to irritation, nipple hardening, and even skin burn.

“Skin around the upper torso and breast is also sensitive to potential injury from repetitive contact with an athlete’s sports bra or uniform, which might result in chafing or lacerations from rigid bra components,” says Christine E. Haycock, M.D., a former Director of emergency services at the New Jersey Medical School.

“Nipple erection can be caused by several factors like physical exhaustion, increased blood flow, hormonal activity, sweating, chafing, or changes in the air temperature,” says Dr. Tezer

For me, it is very common to get hard nipples during running, swimming, or even lifting weights.

Nipples Showing Through My Sports Bra, What To Do?

Nipple erection during exercise is very common in elite female and male athletes in a variety of sports.

According to one study, over 36% of elite female athletes reported experiencing nipple hardening and breast injuries during their sport.

“One of the most common problems among male and female athletes is the “runner’s nipple”, also known as “jogger’s nipple”, according to the article.

Runner’s nipples refer to pain caused by the frictional forces generated between the sports bra or uniform and breast skin.

What can you do if your nipples get hard?

If having gym nipples is something that makes you feel awkward or embarrassed, I recommend changing your sports clothing.

Some materials like cotton are more likely to cause such irritation because they hold more moisture.

On the other hand, polyester is incredibly durable, wrinkle-resistant, and moisture-wicking which means it will cause less irritation.

So go shopping and choose a different T-shirt.

The same goes for bras.

Female nipples get hard in the gym because of the sports bra they wear.

Women who get gym nipples should wear a sports bra that is made from nylon, polyester, or Lycra.

These are soft, delicate, breathable, and lightweight materials that wick away moisture while providing the right amount of support.

How to hide hard nipples in the gym?

You can hide hard nipples in the gym in several ways:

  • Using bandages, athletic tape, or applying anti-chafing products on the nipple during exercise.
  • Placing tapes or wearing compression garments. (It can not only eliminate the friction between the fabric and breast skin but also mask the visible erected nipple.)

I like the idea of wearing bandages because it’s easy and doesn’t require you to spend hours online searching for new clothes.

However, during exercise, your body will be sweating, which will loosen the adhesive of the tapes.

However, what to do if friction is not your main problem, and you’re only concerned about how your nipples look when they get hard and showing through the T-shirt?

I recommend using different colors of clothes. For example, darker colors like black are perfect to mask hard nipples in and out of the gym (I think this is one of the easiest solutions to this problem).


Gym nipples are extremely common and not unusual. Working out can cause hard nipples because of increased blood flow and hormonal activity.

Elevation in sympathetic activity and exercise leads to higher NO production which in itself stimulates nipple erection.

On the other hand, wearing cotton and lose fitted clothes can lead to chafing and irritation of the skin.

Wearing a tight sports bra and fitted T-shirt will reduce friction and helps to eliminate the appearance of hard nipples, as well as reduce irritation from the clothing material.

Michal Sieroslawski

Michal is a personal trainer and writer at Millennial Hawk. He holds a MSc in Sports and Exercise Science from the University of Central Lancashire. He is an exercise physiologist who enjoys learning about the latest trends in exercise and sports nutrition. Besides his passion for health and fitness, he loves cycling, exploring new hiking trails, and coaching youth soccer teams on weekends.

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