When Kim Kardashian Tweeted this picture of herself in her gym kit we couldn't take our eyes off her chest...but not for the reasons you might think.
Exercising isn't about showing off your enormous boobs, Kimmie! In fact, she could be doing irreversible damage to her assets if she continues to wear a bra that is too small.
When you exercise the Coopers Ligaments that hold the breast tissue in place are put under pressure. Lots of moving around causes these ligaments to stretch and tear, which can cause sagging.
And because the breast tissue doesn't contain any muscle this damage is permanent. No amount of exercise or weight lifting can make those bad boys bounce back up!
Researchers at the University of Portsmouth discovered that A cup breasts can bounce 4cm per stride, while a G cup bust can bounce 14cm per stride when running on the treadmill.
Now, we're not sure what size bra Kim K wears, but we're pretty sure she'll be experiencing a lot of movement.
The experts at sports bra retailer, Less Bounce, have this advice for buying a perfectly fitting sports bra...
+All of your breasts should be encased in the bra. You shouldn't be able to see any cleavage - take note Kim.
+The fit should be snug - not so tight that you can't breathe, but tight enough that your bust doesn't move around when you walk.
+You shouldn't be able to fit more than one finger under the bra (across the back and around the front).
+Put two fingers underneath the back strap and pull out - you should only be able to pull the strap an inch away from the body.
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