Blessed are the flat-chested, for they will never know the struggle of having to use their arms to hold their boobs down as they race up a flight of stairs, or having to layer sports bras just to go for a jog. A nice rack may look great in a dress or a low-cut top, but they’re definitely not always comfortable. How could they be, when they move an average of nine centimeters in a figure-eight motion—up, down, and sideways—with each step a woman takes?
With that said, our anxiety about drooping boobs as we age is pretty much validated. It’s a fact that, because of this constant movement, breasts travel the older a woman gets, as elasticity in skin starts to decline. The way they move can even indicate your age: A study conducted by the Research Group in Breast Health at Portsmouth University used sensors and 3-D scanning software to monitor the busts of two sets of women, aged 18–25 and 45–65, during brisk walks. The young women’s breasts moved up and down—hence, bouncing!—while the older group’s boobs moved more in all directions.
And the agony of breast pain isn’t just a thing we whine about with our gym buddies: In fact, it’s so universal that there’s actually a world expert in breast biomechanics. Her name is Professor Joanna Scurr, and she knows all there is to know about your boobs. One of her pet subjects is the degree to which women are put off by sports based on their breast discomfort alone.
More than 50 percent of women experience breast pain when exercising because breasts move more than most ordinary bras are designed to support, according to a 2007 study conducted by Dr. Scurr. And not all sports bras are made alike—wearing the same style all the time may not even protect your boobs. “Movement of the breast varies from sport to sport,” Dr. Scurr says. Runners in particular need compressive bras that will hold ’em down from all angles.
Even swimming is rough on breasts. A study in the Journal of Sports Sciences says that boobs still move as they travel through water, with a front crawl causing the most movement. However, larger-breasted women do experience some natural breast support thanks to the “buoyant force of water,” but Dr. Scurr says that breasts still move “quite a lot” with each movement. Researchers even suggest wearing a sports bra in the water to significantly reduce the wear and tear on the bust. A high-neck, supportive swimsuit can also do the trick.
Without preventative measures, the ligaments in your breasts can stretch to as much as 15 centimeters by late old age. The “drooping process,” called ptosis, often results in breasts that have traveled more than three centimeters downward from their pubescent position, and the nipples tend to point downward. If this is all supporting your case for making like Marilyn Monroe and wearing a bra to bed, you’re on the right track: There’s truth to the myth that women worried about sagging can benefit from wearing a bra while they sleep. “There are no negative factors associated with wearing a bra all of the time,” Dr. Scurr says. So if larger-breasted women find it more comfortable to keep theirs on overnight, there’s no reason not to.
A sagging bosom, multiple sports bras, an extra-supportive swimsuit … among all these complications, we’re kind of starting to regret spending our adolescent years hoping and praying that we’d finally develop some tits by the end of the school year. Sigh.