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Catalyst Sports Bra
High Support
Catalyst Sports Bra
$78.00
USD
10% off Bra & Underwear Sets*
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.
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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
Sports Bras Comparison Chart
Catalyst Sports Bra
Maximum support
Full coverage
Reduces bounce by 76%
Momenta Racerback Sports Bra
Medium support
Mesh underband for ventilation
Pullover style
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
Total 5 star reviews: 3.8k Total 4 star reviews: 795 Total 3 star reviews: 274 Total 2 star reviews: 177 Total 1 star reviews: 231
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 2 weeks 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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Purchased Knix Size - Catalyst
5,277 reviews
- Rated 5 out of 5 stars4 minutes ago5 Stars
I needed a better sports bra to accommodate my postpartum/breastfeeding body. This is by far the best sports bra I have ever owned. It offers so much support and is very comfortable.
RaynaReviewingCatalyst Sports Bra - Rated 3 out of 5 stars18 hours agoOk
Smashes you into a bra, uncomfortable for me and you sweat a lot
Roseann S.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 starsYesterdayVery satisfied
Love my sports bras. Very comfortable and supportive.
Robin W.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 starsYesterdaybest sports bra on the market
absolutely love the Catalyst! comfortable and holds everything in place - no bounce during high impact workouts. and the pattern is fun!
(would ignore the Purchased Knix Size - Catalyst, when I checked it showed XXXL+, and that wasn't a listed option to select)
Catherine P.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars2 days agoCatalyst bra
Love my catalyst bra
I actually wear it daily
It fits well
Love it
Thx
Destiny D.Verified BuyerReviewingCatalyst Sports Bra - Rated 2 out of 5 stars5 days agoCatalyst sports bra
I wish the straps were longer… the bra keeps riding up on the longest setting… which can get uncomfortable and awkward to adjust when already dressed. Either a mistake in construction or the sizing chart is wrong!
Karin A.Verified ReviewerReviewingCatalyst Sports Bra - Rated 4 out of 5 stars5 days agoComfortable bra!
Soft material; love the fit on bra straps and across the back. I had to return twice for correct fit. I’m 32 F and ordered size L per the size chart. I still had spillage, so had to return the sports bra.
Mercedes B.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars5 days agoSuper comfortable
Very happy with how well it fits and supports during high intensity sports.
Karin G.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars1 week agoSport bra that’s a perfect fit
I’m glad they have a 30 band with a large cup size. So pleased. Great fit!
Jeannie W.Verified BuyerReviewingCatalyst Sports Bra - Rated 5 out of 5 stars1 week agoExcellent Running Bra
Great bra for running! Comfort and support!
Shelley G.Verified BuyerReviewingCatalyst Sports Bra - Rated 2 out of 5 stars1 week agoStraps scratchy
This bra was my favourite fit but the straps were so scratchy and irritating I couldn't wear it.
Erika D.Verified ReviewerReviewingCatalyst Sports Bra - Rated 3 out of 5 stars1 week agoA little disappointed
Was frustrated to find a tag inside my sports bra (a very scratchy tag) . When bought previously there was no tag inside...which was a selling point for me
Lori B.Verified BuyerReviewingCatalyst Sports Bra
