Buying the right sports bra can be a huge pain—literally, if it doesn't fit. But Nike has your back (and your boobs). The brand posted four tips to find the perfect sports bra on the NikeWomen Instagram account. Of course, Nike wants to sell more products, but this time it comes with advice women can use (and models who actually look like them when they wear a sports bra).

Welcome to Sports Bra 101: Most women wear a band too big and cup too small. Raise your hands above your head. If the band moves up, you may need to size down.

Gravity isn’t your BFF: No matter your chest size, gravity can cause tissue damage while you move—sports bras protect you from this.

Hold tight: Sports bras are designed to take on more impact than regular bras—this is why the band of your sports bras should fit slightly tighter than your everyday bra.

Say hello to support: Motion causes breasts to move in a figure eight, and cupped designs can provide higher support for bigger breasts.

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