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Catalyst Sports Bra
High Support
Catalyst Sports Bra
$78.00
USD
Our most supportive sports bra
Eliminates bounce by 76%
Ventilation for increased airflow
Full coverage design
Size and Fit Guide
Use Our Calculator to Find Your Traditional Bra Size
Step 12 of 2
Your Results
Measure Your Under Bust
Measure Your Full Bust
Wearing an unpadded bra, wrap a measuring tape around the top of your ribcage. You’re looking for a snug fit - so we recommend tightening on the exhale and noting the smallest measurement to the decimal.
Wrap the measuring tape around the fullest part of your chest, making sure the measuring tape is paralell to the floor. Relax your shoulders and measure where it falls.
At Knix, your size is
Still have questions? Ask our virtual assistant about finding the perfect fit.
Still have questions? Reach out to info@knix.com to learn more about our sizing.
Rewards Members Earn
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Product Description
High Impact Support
You are in control of your performance with our most supportive, full-coverage sports bra.
Feels Made For You
The traditional adjustable hook and eye back closure, featuring five rows, allows you to find the perfect fit easily.
Functional Style
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How to Choose?
Essential
- • Days you don’t need leak protection. Everyday freshness and moisture wicking.
-
0 tsp
Heavy
- • Extra peace of mind. For the first days of your cycle, light bladder leaks, or a full night's sleep without a leak.
-
about 8-14 tsp
-
about 1.5-3 regular pads
-
about 4-7 super tampons
-
about 1.5-3 menstrual cups
Light
- • Daily freshness. For sweat, discharge, period spotting, or backup protection.
-
about 1-3 tsp
-
about 1-3 pantyliners
-
about 1-3 regular tampons
-
about 0.5 menstrual cups
Moderate
- • For mid-cycle flow, surprise cough or sneeze leaks, or a really sweaty spin class.
-
about 4-8 tsp
-
about 1-1.5 regular pads
-
about 2-4 super tampons
-
about 0.5-3 menstrual cups
Ultra
- • Ultimate peace of mind. For the heaviest period days, light bladder leaks, unexpected postpartum flow, or overnight protection.
-
about 15-20 tsp
-
about 1.5-2.5 super pads
-
about 7-11 super tampons
-
about 2-3 menstrual cups
Comparison Chart
Catalyst Sports Bra
Maximum support
Clasp back closure
Reduces bounce by 76%
Restore Sports Bra
Light support
Padding-free
Pullover style
Momenta Racerback Sports Bra
Medium support
Mesh underband for ventilation
Bra top with sewn-in padding
Longevity Sports Bra
Light support
Bra top with bonded-in cups
Pullover style
HIGH IMPACT SPORTS BRA
High Impact Support
Reduces Breast Movement
Tri Flo Ventilation
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Recently Viewed
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 3 months ago
Customers say this sports bra provides excellent support and comfort for larger busts, with many wearing it all day. The wide straps and molded cups offer secure hold during high-impact activities like running and weightlifting. Many reviews mention the soft, breathable fabric and flattering fit without underwire. Common feedback includes concerns about sizing changes, with several noting the need to size up from previous versions. Some experience issues with strap placement and adjustment, particularly with newer models where straps may loosen or slip. While most praise the durability and long-term wear, a few mention quality concerns with adhesive or hardware over time.
90%would recommend this product
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5,310 reviews
- Rated 5 out of 5 stars4 minutes agoComfy Fit
I enjoy this sports bra and have the light blue as well.
SGShawna G.Verified BuyerReviewingCatalyst Sports Bra - Rated 3 out of 5 stars11 hours agoStrap length
The straps could be about an inch longer. The bra tends to pull up too much. I often have to pull it down
SNSusan N.Verified BuyerReviewingCatalyst Sports Bra - Rated 4 out of 5 stars12 hours agoCatalyst sports bra
I really like it but there is a bit of puckering near the armpit area despite how tight I make it. I did however buy a Knox bra several years ago which us a catalyst bra and it fits to a T and I love love love it. It has a hook adjustable straps which I also really like.
WKWendy K.Verified BuyerReviewingCatalyst Sports Bra - Rated 3 out of 5 stars3 days agoGood support
Like this bra, bought a size too big so will return and get that.
JMJeannie M.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars5 days agoGreat purchase
Love this Sports bra. Great support and looks great
LJLinda J.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars5 days agoThis large chested girl is happy!
I am generously endowed in the chest. For most of my adult life, I have avoided sports or pasttimes that require me to run as the chest bounce was really uncomfortable.
Then we got a dog and decided to show him. I now literally run around a ring with my large dog on a leash and make him look pretty. This bra has saved me! The comfort of this bra and the support is amazing! And the fact that it doesn't do the uniboob smoosh is a really nice detail.
JRJanet R.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars1 week agoSupport and Comfort
So comfortable for moving without bouncing and holds the girls up! I am using a band extender till it relaxes a little bit.
MAMarianne A.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars1 week agoGreat sports bra
I'm really happy with this bra, that is not underwire. I purchased three so far and have told friends about it.
LBLori B.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars1 week agoRunning Holy Grail
I’ve been running for years in some pretty terrible sports bras and knew it was time to invest in a good one. The staff at the Westboro store helped me picked The Catalyst and it is incredible. Everything stays in place and I honestly forget I have it on. Will be buying a few more so I’m never without it on any run.
LALeanne A.Verified BuyerReviewingCatalyst Sports Bra - Rated 4 out of 5 stars2 weeks agoNot My Favourite
Not as comfortable and supportive as I had hoped. Maybe a cup size and band size higher would have helped.
TGTracey G.Verified BuyerReviewingCatalyst Sports Bra - Rated 3 out of 5 stars2 weeks agoWas trying to replace old version
Liked the old version better. Fit isn’t great, cups are too molded into a weird shape
ADAmy D.Verified BuyerReviewingCatalyst Sports Bra - Rated 1 out of 5 stars2 weeks agoCatalyst Sports Bra
If you like a monoboob, this is for you. It is essentially a constriction device.
HMHeather M.Verified BuyerReviewingCatalyst Sports Bra
