The best sports bra is one that enables you to lead an active lifestyle in comfort and with minimal chance of injury. Whatever your cup size, you need good support so you can focus on your sport.

This article gives you basic information about sport bras so you can shop with confidence.

Shop REI's selection of sports bras.

Consider Your Impact Level

The amount of jostling and movement associated with your favorite activities is one factor that helps dictate the best sports bra for you. This is categorized by "impact level."

Low-impact Medium-impact High-impact
  • walking
  • road cycling
  • weight training
  • yoga
  • moderate hiking
  • skiing
  • inline skating
  • running
  • aerobics
  • mountain biking

Find Your Sports Bra Type

Sports bras minimize breast movement through several approaches.

Compression bras are best for A and B cups. They compress the breasts against the chest wall to restrict movement. Compression bras come in 2 basic styles: Scoop-back styles work well for women during low- or medium-impact activities. Racer-back styles are more supportive and are better for medium- and high-impact activities. Thin spaghetti straps provide less support than wider straps.

Compression/encapsulation bras are best for C and D cups. These "combination" bras combine the above 2 methods into a supportive and comfortable style. These bra offer more support than compression alone.

Encapsulation bras are best for D and DD cups. They use individual cups to surround and support each breast separately. There is no compression in these bras (most everyday bras are encapsulation bras).

Alternatively, shimmels are tank tops with an integral shelf bra that provides support for low- or medium-impact activities.

The Basics of Sports Bras

The support offered by a sports bra is necessary for active women. Your chest includes suspensory ligaments known as Cooper's ligaments. These ligaments hold breasts up and give them their shape and size. Once stretched, Cooper's ligaments do not recoil to their original position. Sports bras protect the anatomy of a breast by reducing stretching and stress on the breast tissue.

If you participate in many different activities, it's smart to equip yourself with several different styles of sports bras—ones with more support for high-impact activities and some less constrictive ones for low-impact activities.

When shopping, consider the following bra features:

  • The band around the bottom is the foundation of a bra. It provides much of a bra's support. Wide bands are more supportive than narrow bands.
  • Shoulder straps hold up the cups but are not the main support of the bra. They should provide minimal stretch to reduce up-and-down movement. Wide straps better disperse the weight and offer greater comfort than narrow ones. Straps should not slip off or press into your shoulders during high-impact activities. Adjustable straps allow you to customize the fit.
  • Underwire is a metal or plastic reinforcing material that runs along the bottom of the cup. It is usually flexible and moves with your body to help prevent injuries. An underwire provides extra support and shape to any bra.
  • Wicking fabrics move moisture away from your skin and keep you comfortable. The more supportive a sports bra is, the less effective it will be at wicking away moisture because of its sturdier fabric and construction.

Find Your Sports Bra Size

how to fit a sports bra

Surprisingly, it's estimated that 3 out of every 4 women wear an ill-fitting bra. No fitting system is foolproof, but the steps below are considered by industry experts to be the best way to find your size.

  • Step 1: Band size. With your shirt off, measure around your rib cage, just under your breasts, at or just below the band of the everyday (lingerie) bra you are wearing. The tape measure shold be snug but not interfere with normal breathing. Take this rib cage measurement, add 5" and round up to the nearest even number. For rib cage measurements 33" or higher, add 3" and round up to the nearest even number. This is your band size.
  • Step 2: Bust size. Measure loosely around your bust at the fullest part. Be sure the tape stays straight across your back. Round up to the nearest whole number.
  • Step 3: Cup size. Subtract your band size (step 1) from your bust measurement (step 2). Use the resulting number to determine your cup size as follows:
Difference 1" 2" 3" 4" 5"
Cup size A B C D DD

Now, let's put it all together. For example, let's say:

  • Your rib cage measurement is 28". Add 5" and your band size is 33".
  • Your bust measurement is 35.5". Round up to the nearest whole number: 36".
  • Subtract 33 from 36. The 3" difference means you should wear a C cup.
  • You are a regular trail runner. This is a high-impact activity.

Result: You should shop for a size 36C compresssion/encapsulation style of sports bra.

Perfecting the Fit

When trying on a sports bra, check the following things:

  • It should fit slightly tighter than a regular bra, but not so tight that you can't comfortably take a deep breath with the bra fastened on the middle hook.
  • There should be no chafing around the armholes, shoulder straps or seams. If the sports bra has hooks or snaps, make sure those don't chafe, either.
  • The straps shouldn't dig into your shoulders.
  • To make sure you have the right size, raise your hands over your head. If the elastic band moves up your rib cage, you need a smaller band or the straps may need to be adjusted.
  • The cup fabric should be smooth. Wrinkles or puckers indicate the cup is too big.
  • Test the bra's support by jumping or running in place. You'll be able to feel whether it's sufficiently supportive or not.

Sports Bra Care

Most sports bras last about 6 to 12 months. To maximize the lifespan of your bra, always hang dry it rather than use a machine dryer. While most sports bras are machine washable (in gentle cycle), this does tend to shorten its functional life. Hand wash if possible and always avoid using fabric softeners which can inhibit the moisture-wicking properties of the fabric. It's also best to fasten the hooks before putting your bra into a washer.

Signs that your sports bra is near the end of its useful days:

  • The fit seems too loose or big.
  • Vertical (up and down) movement has increased.
  • The fabric is pilling.
  • You can't read the care label anymore.

Contributors: Teresa Ross, Moving Comfort sales representative; REI Alderwood (WA) store staff; Kristin Finton, REI product manager.