Does Running Affect Your Breasts?

Amazing: while breasts are one of the most admired part of the female body, there’s very little research that’s gone into the impact that running and exercise has on a woman’s chest.

Dr. Joanna Scurr (principal lecturer in Biomechanics – Sport and Exercise at a university in the UK) – stepped up to the challange.

On paper, her studies are referred to as “breast biomechanics”, but Dr. Scurr prefers to chat about it as “bouncing breasts”. No beating around the bush with this lecturer!

Here are some of her answers and tips about your bouncing bits:

What happens to our breasts while we are running?

During walking, a woman’s breasts move the same amount in and out, up and down and from side to side: about 33% in each dimension.

Up the pace to a jog or a run, and the movement is split: 51% up and down, 22% side to side and 27% in and out. The overall pattern is a figure of eight (on it’s side).

Breasts move as much during a slow jog as they do during a sprint, meaning no matter what your pace, you should always wear a sports bra!

Long term damage?

Ladies, it’s a simple answer: wear the incorrect bra and irreversibly stretch fragile ligaments, leading to sagging.

Keep the muscles that support your breasts firm to reduce sagging by doing these exercises.

So what bra should I wear?

The best bra for exercise is an encapsulation bra, which has separate moulded cups rather than a compression bra which flattens the breasts to the chest wall. This is because each breast moves independently. Compression bras flatten the breasts, limiting the bounce, but not the side to side or in and out movement. Separate cups limit this movement.

Make sure your bra fits correctly. Don’t forget that bra size fluctuates throughout your lifetime!

I have “bee-stings” – do I still need to wear a bra?

Yes! In A-cup women, the wearing of a sports bra reduced breast movement by 53%. In G-cup women, sports bras reduced movement by 55%.

Convinced? Here are our top bra picks.

Got something to say?

11 Responses to “Does Running Affect Your Breasts?”

  1. Sandy says:

    I’ve been running since I was 22 and either with a cheap Walmart sports bra or none in the winter (they make a sweaty rash in the winter). I’ll be 59 in November, Went to a plastic surgeon for carpal tunnel and his first question was “You’ve never had kids have you?” That was true. Years ago I read a doctor’s article said that running without a bra could actually make you sag less. I have very firm breast and sometimes even a tight workout tank under my regular clothes is enough although the headlights come through loud and clear.

  2. Penny Ritter says:

    Your competition site for Triumph bra does not work

  3. The competition is closed, Penny. :(

  4. Tracy says:

    This is actually not true. A bra weakens your muscles by doing their work for them. Women went braless for millennia and there is no evidence that their breasts sagged more than those of women today who wear bras all their lives.

    I ran braless as a teen with no impact. Then I bought into this lie. A year ago, I took off my bra again. A 50 yr old woman running bra-less for a year — in fact my breasts are more “perky” than ever.

    A bra is something you should wear if it makes you feel more comfortable, that’s all.

  5. Robert Solomon says:

    The data Dr.Scurr has provided speak of motion – lateral motion, vertical motion, complex rotatory motion. In fact,many parts of the body are in motion of this kind during running. And during running, the interplay of gravitational forces and abrupt changes in momentum will generate stretching forces on muscles, ligaments and other connective tissue. She has presented no evidence that any of this leads to sagging or permanent deformation.

    My specialty in medicine is NOT breasts. But with regard to the issue of breast feeding, which also has been accused of leading to sagging breasts, similar arguments have been proposed. However, with breastfeeding, it is taught that the enzyme elastase weakens connective tissue during pregnancy (to help with the widening of the pelvis necessary for birth). It is PREGNANCY that has the effect of leading to breast sagging, not the increased mass of the breast and gravitational forces, nor increased momentum leading to increased stretch.

    There are contrary points of view in the medical field: Robert Mansell, a professor of surgery at the University Hospital of Wales, in Cardiff, reported that, “Bras don’t prevent breasts from sagging, with regard to stretching of the breast ligaments and drooping in later life, that occurs very regularly anyway, and that’s a function of the weight, often of heavy breasts, and these women are wearing bras and it doesn’t prevent it.” John Dixey, at the time CEO of Playtex, agreed with Mansell. “We have no medical evidence that wearing a bra could prevent sagging, because the breast itself is not muscle so keeping it toned up is an impossibility.”

    I cannot help sort through the different claims, but motion during running is not the same as sagging. It may lead to sagging, or it may not. One could also conjecture that ligaments may adapt to the strain put on them, so running without a bra is better tolerated if one does not ever wear a bra.

    There were many arguments about the necessity of running with shoes, and over time, these have given way to arguments in favor of running barefoot. This, too works better for those adapted to walking and running barefoot all the time.

  6. Robert Solomon says:

    It is not a question of muscles. Breasts are not supported by muscles. They are supported by ligaments. Those ligaments may relax with time and aging (and with pregnancy, regardless of breastfeeding). They may not. It is different for different people, anecdotal stories notwithstanding. I would like to learn if there is accurate recorded data of breast ptosis recorded historically before the invention of the brassiere. By the way, that word is French for ‘arm protector’, a mysterious word indeed.

  7. The above comments are broadly correct. The breast is shaped and positioned by its composition, the skin, the fascia which encapsulates it and the internal septa, or suspensory (Cooper’s) ligaments which run through it. Its position is also determined by its attachment to the anterior chest wall by the retromammary fascia and by the shape of the chest wall itself.
    Movement of the breast is not in itself harmful but may result in pain in some women. That pain diminishes over time.

    Recent research shows that female athletes exercising without bras actually experience firmer and higher breasts. Bras are not necessary when running or for any other form of exercise. If breast pain limits your participation in sports, restraint by certain (but not all) sports bras may limit movement and improve symptoms, but generally the breasts will adapt to a lack of restraint.

    1. Soutien-gorge de sport, in Thierry Adam, Gynécologie du sport. Springer 2012, pp 305-309
    2. Facteurs de l’évolution morphologique du sein après arrêt du port du soutien-gorge : étude ouverte préliminaire longitudinale chez 50 volontaires. Olivier Roussel; Jean-Denis Rouillon; Université de Franche-Comté. Faculté de médecine et de pharmacie. Thèse d’exercice : Médecine : Besançon : 2009.

  8. Robby says:

    Major bra manufacturers make no health claims. It is the minor niche bra makers that make the health claims, which are unsupported by unbiased independent research.
    Certainly obese breasts can put a heavy stress on the skin, the primary breast support. Obese bellies likewise put great stress on the skin, and sag. Pregnancy is not the same as it swells inside the net of abdominal muscles and ligaments while obesity is composed of a mass of mostly fat outside of the abdominal wall.
    An apt comparison is made of breasts, which are mostly fat, and a thick-walled, slightly stretchy, balloon filled with gelatin (“Jello”). If the filler is reduced the envelope, the skin or the balloon, will “deflate” and the envelope will flatten and sag.
    Extreme stress such as a car collision can overload the skin of the breasts, even causing tearing, just as collisions can break and tear other body parts. Punching the breasts as in boxing can break down the internal structures of the breasts.
    However, normal activities, running, gymnastics, pose no danger to healthy breasts (obesity is not healthy) and contribute to their health and appearance (mostly height on the chest, the great worry of women).
    Exercise causes discomfort of many parts of the body. If one concentrated on discomfort, one would be conscious of discomfort of the feet, ankles, and other stressed parts.
    A common source of pain is nipple chafing, which is not limited to women. If the shirt is loose and does not stretch with movement, or if the breasts move around inside a bra, nipples may become sore and even bleed, especially small undeveloped ones (like men’s). A snug fitting stretch shirt that moves with the breasts rather than them rubbing against the inside of the shirt helps avoid chafing.
    Something that has been overlooked (at least |I have not seen it) is that if the outer envelope (skin) of the breasts is held rigidly, preventing all or nearly all movement of the breasts on the chest, the internal organs of the breasts, mostly milk glands and ducts, will “joggle” around inside the breast, for fat is not only semifluid, it is spongy, not holding the organs still inside the outer envelope (skin). This is not a natural movement. It is akin to the movement of organs internal to the torso that is exaggerated by heavy loading and impact as experienced by fighter pilots, earthmoving equipment, freight trucks on rough roads, etc. These organs can be chafed in a sense even though the body fluids lubricate them, and even bruised from agitation.

  9. Kaybie says:

    Please compare the bra wearing societies to the non-bra wearing societies of today for your answer. It seems that in all documentaries on back-country tribes, even women in their 20 have very saggy breasts.

    I’ll keep my bra, thanks.

  10. Hannah says:

    Does this change if you wear a sports bra

  11. XLNTMOMMY says:

    I agree !
    Childbirth I think affects the breasts far more than jogging ..
    also weight gain/loss ..!
    I wear ~two~ bras when I jog, or even walk .. a regular bra underneath a jog-type, spandex bra .. it works !

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