The 3 Impact Levels of Sports Bras

April 19, 2023
Team Knix

Whether you're a runner, track star, yogi, stair master, competitive frisbee-thrower, or floor stretcher—we know a good sports bra can make all the difference. Feeling comfortable and supportive in your gear while you're working out can be a very literal game-changer. But where to start? 

Finding the right sports bra can feel harder than qualifying for the actual Olympics. If searching for the right look, fit and support isn't challenging enough, there's also the question of sports bra impact levels. And with that comes a bit of a puzzle.

What do they mean, and how do I find a sports bra that matches my movement? Join us on a crash course about sports bra impact levels, so you'll know exactly what to run toward for your next workout. 

Sports Bra Basics

Knix Activewear, featuring the LeakStrong Leakproof Short and LeakStrong Leakproof Skort in Dahlia display: full

When it comes to sports bras there are generally three main impact levels, which refer to the effect the movement or activity may have on the body. In the case of running shoes for example, when they refer to “impact,” they're talking about the pressure on weight-bearing joints like your knees and hips.

But in the case of sports bras, we're talking about the effect the activity may have on your breasts (that's just gravity, baby). The higher the impact level, the greater degree of breast movement, and the greater the need for support.

You should always try and wear a supportive sports bra when moving and grooving, no matter your breast size. Even if you wear a 34A — if you don't wear a sports bra when working out, you run the risk of damaging and stretching the breast ligaments, which could result in long-term issues like back problems and shoulder pain. 

Read on to learn more about the three impact levels of sports bras, what they mean, and the best sports bras for every kind of movement, workout, or activity (and yes, running errands counts).

Low-Impact Sports Bras

Low-impact sports bras are designed to provide support for movement sessions and workouts (AKA a low degree of bounce). With light, comfortable support, low-impact sports bras are a great option for those with smaller breasts, or for more gentle exercise.

Low-impact sports bras typically work well for people with cup sizes A through D. If your breasts are larger, it may be best to move up an impact level. But lots of folks all cup sizes like to wear low-impact bras as lounge or sleepwear. The rule of thumb here is simple: whatever works for your body!

Many people like to wear low-impact sports bras for lounging around the house, when out for a walk, or to a yoga or pilates class. If your breasts are on the smaller side, you may find them supportive enough for hiking, cycling or weight training.

Check out our Longevity Bra and Revolution Adjustable Pullover Bra, which both feature adjustable straps and comfortable support for low to medium impact workouts for the perfect fit.

Medium-Impact Sports Bras

Momenta Racerback Sports Bra in Dahlia display: full

Medium-impact sports bras are designed with extra support for all bust sizes. Typically, these bras come with a slight degree of compression and fit snug to the body for the right support while you sweat it out.

Depending on your breast size and the degree of lift and support your girls require, medium support bras can be the ideal go-to for both low-impact and high intensity workouts—okay versatility!

These bras can be worn for activities such as yoga, golf, hiking, weight training, martial arts, cycling, or using the elliptical, while those with larger breasts may find them more comfortable and supportive for walking or everyday wear.

The Momenta Racerback Sports Bra is perfect for medium-impact activities. It's a wireless fit, made using BlissFit Fabric for a body-hugging feel that adapts and contours to your every move. 

High-Impact Sports Bras

The Catalyst Sports Bra in Arabesque and Momenta Racerback Sports Bra in Vapour display: full

High-impact sports bras are designed for activities that involve a lot of jumping or movement that may result in breasts bouncing. They are usually made with a high degree of compression and are built with a lot more support in the straps and bottom band.

Because of the additional support, high-impact sports bras are essential for people with larger cup sizes. That being said, people of all bust sizes can benefit from the support they provide—especially if you're in for an intense workout.

High-impact bras provide the right amount of support for high intensity workouts that involve a lot of vigor and breast movement. These bras can be worn for sports like running, kickboxing, horseback riding, and HIIT. (We also recommend them for any and all dance parties). 

If you're looking for a high-impact sports bra, The Catalyst sports bra is your ticket to jiggle-free movement. The molded cups separate and encapsulate your breasts to reduce movement, and is made to mold to your shape.

The Catalyst sports bra comes in a front closure version, too. The Catalyst Front Zip sports bra is a great option if you have mobility issues, a limited range of motion, or just want the option to show off a little cleavage. It's also super easy to take on and off (no matter how sweaty you get). 

Our Activewear collection supports in all the right places, designed with your comfort in mind. So, you can run, play, and chill in super supportive sports bras, booty-enhancing leggings, and more.