We’re used to hearing the old adage, “The bigger they are, the harder they fall,” but when it comes to large breasts and strenuous activity, you can add:

“The bigger they are, the higher they fly”

“The bigger they are, the more they bounce”

“The bigger they are, the harder it is to make them behave”

Although our smaller busted friends can learn a thing or two from how our breasts react to the forces of exercise, it is the buxom among us who must carefully protect our “girls” from the unrelenting attack of Newton’s Laws of Motion. Before choosing a sports bra for your large breasts, it’s good to know a few things about how your breasts behave when you exercise.

• 1) Your breasts have little natural support. Tiny ligaments and your skin do most of the work. During strenuous exercise this connective tissue can be permanently stretched, resulting in sagging, stretch marks, and pain. As a result, many women (of all sizes) stop exercising completely.
• 2) Your breasts move in three planes of motion during exercise: Up and Down, Left and Right, In and Out. A 2007 study in the UK found that breast motion while running is 51% in the “up and down” plane, 22% in the “left and right” plane and 27% in the “in and out” plane. You have our permission to impress your friends with this fact at your next cocktail party.

Traditional compression type sports bras, like the New Balance Fit Crop Top (left) reduce motion only in the up and down plane. So, even an effective compression bra misses nearly half of the motion your breasts experience during exercise. Encapsulation bras – bras that enclose each breast in a separate cup – are much more effective at reducing the side to side motion in addition to the up and down motion. That leaves only the in and out motion to conquer!

Unfortunately, a bra hasn’t yet been invented that can reduce the in and out motion. So, the best we can do for now is to find a hearty sports bra that encapsulates and compresses. Here are a few of our recommendations:

• 1) Freya Active Underwire Sports Bra. A favorite of our friend Rachel over at the Intimate Guide, this sturdy bra is capable of standing up to high impact activity like volleyball and running.
• 2) Lunaire Coolmax Underwire Sports Bra. Winner of the 2009 Undie Award for best full figure sports bra, this bra from Lunaire is praised for its quick-dry magic and breathability.
• 3) Pure Lime High Impact Wire Free Compression Sports Bra. Not your typical compression sports bra, this high impact bra from Pure Lime features a revolutionary design with a side compression panel to reduce the side to side motion as well as the up and down motion.