How Should Sports Bras Fit?

A woman taking off her shirt to reveal a sports bra

Our Nifty Little Guide to Finding the Perfect Fit

You probably know the importance of proper fit when it comes to your running shoes. And finding the right fit in a sports bra is just as important! Many women don’t know what size bra they should be wearing, or struggle to find the right fit. Wearing an uncomfortable bra can cause breast pain, chafing and distraction mid-activity. It can also cause long-term damage to your breasts, which nobody wants!

So, chances are, if you’ve never been fitted for a sports bra, you could be running in the wrong size. Fleet Feet specializes in bra fittings. You can schedule an appointment at most locations to make sure you get an Outfitter that you’re comfortable with.

To find the right bra for you, you need to determine your size, as well as the activity you’re using it for. If you’re doing a high-impact sport, like running, you need a high-impact bra designed to comfortably support you for that type of movement.

We’ve put together this handy guide to help you determine the right size, and know how to tell if your bra fits properly.

A runner wearing a sports bra starts her watch before a run.

Gather a few measurements

A sports bra sizing chart

To find the optimal size, use a measuring tape to assist you with the following measurements. You’ll also need to do a tiny bit of math.

1. Find your band size. Take the measurement just above your breasts. Round down to the nearest whole number and record the measurement.

2. Measure your bust. Place the tape around the fullest part of your bust, and record that number, too.

3. Find your cup size. Now for a little math: Subtract the two measurements. The difference in inches translates to your cup size (see chart to the left).

For example, if the measurement you took above the bust is a 36, and the measurement you took of the fullest part of the bust is a 39, you would subtract 36 from 39 and come up with three. A, B, C— 36C is an ideal size to try first.

Once you have an idea of what size you need, try on some bras. Different brands have variation in sizing. Get a feel for different sizes and styles to see what you like best.

Low-, medium- or high-impact?

Your activity and your breast size both determine the level of support you need. Most sports bras come in three categories: low-impact, medium-impact and high impact.

As you might guess, a low-impact sports bra is ideal for squats at the gym or a yoga class.

A medium-impact sports bra works well for hiking and cycling.

For the majority of women out there, a high-impact sports bra is ideal for running, mountain biking, dancing, and other intense cardio activities.

However, many smaller-chested women will have no problem performing high-impact activities (like running) in a medium-impact sports bra.

Encapsulation or compression?

Bras come with a variety of support options that use encapsulation, compression, or combination of the two. Let’s break down the differences.

1. Encapsulation bras use individual cups to support breasts by encapsulating them separately. This offers minimal breast support (everyday bras are often purely encapsulation bras). Encapsulation bras are ideal for low-impact activities.

2. Compression sports bras work by compressing the breasts to prevent movement. Most compression bras don’t have hook and clasp closure. Instead, they’re easily pulled over the head. Compression bras are ideal for medium-impact activities.

3. Combined compression and encapsulation bras offer a combination of these two support systems that makes them ideal for running and other high-impact activities.

How can you tell when the fit is right?

A properly fitted bra should feel comfortable. Here are some things to look for in the right fit:

  • When you try on the bra, run in place, twist, bend and jump. Some breast movement is natural, but you shouldn’t feel a lot of bouncing.
  • The fit should feel snug, yet comfortable. If you can hardly breathe, the bra is too small.
  • The band should lie flat against your body and not raise up off of your skin.
  • You should be able to slide two fingers between the band and the body.
  • Shoulder straps should lie flat and not be twisted.
  • Straps should not dig into your shoulders.
  • The cups of the bra should fully cover your breasts. If your skin is showing around the edges of your bra, you might need a bigger cup size for better coverage.

An old bra (even your favorite!) no longer does its job

Know when to replace your bra. Every time you wear and wash your sports bra, the elastic stretches, and will eventually wear out. If you’re using your bra several times a week (four days of running, for example), you should aim toreplace your sports bra every six to eight months. Refreshing your bras regularly will help make sure your breasts get the support and protection they need.

Want to increase your bra’s life? Buy a few at once, so you always have one on hand to wear that’s clean, one in the wash, and one to spare.

Keep Reading