95% Australian superfine merino
Finer than hair, so no itch.
Naturally odour-resistant
Stay fresh longer between washes.
Temperature regulating
Comfort across warm + cool days.
OEKO-TEX® certified
Made with care for sensitive skin.
The Medium Impact Racerback Bra is women's natural fibre activewear - a merino wool sports bra made from 95% merino wool, with no polyester. A low tox alternative to synthetic sports bras, designed in Australia for women wanting extra support without plastic-heavy fabrics.
More support. Naturally.
Designed for medium-impact movement, this merino wool sports bra provides a more secure feel with a supportive racerback design, wider shoulder straps and a thicker underbust band for added stability during training.
Made from super-fine merino wool, it feels soft against the skin while naturally helping regulate temperature and resist odours. The higher coverage silhouette and removable padding make it equally comfortable for workouts or all-day wear.
Why you'll love it
95% merino wool, 5% elastane – natural performance without plastic-heavy fabrics
Medium-impact support – designed for higher support than our other bras
Wide underbust band – secure, comfortable fit without digging in
Wide racerback straps – enhanced support with unrestricted movement
Higher coverage – for those who prefer a little more coverage
Breathable & odour-resistant – wear more, wash less
Soft, supportive stretch – no dig-in, no cling
Removable padding – adjustable coverage
Lightweight & shape-holding – keeps its fit over time
Designed in Australia using premium ultra-fine merino fibres
Why women choose this over polyester
No plastic feel when sweating
Gentle on sensitive or hormonal skin
Medium support without relying on polyester-heavy fabrics
Comfortable enough to wear beyond workouts
Model & sizing
| Estroni merino | Polyester activewear | Cotton | |
|---|---|---|---|
| Stays fresh between wears (odour-resistant) | ✓ | ✕ | ✕ |
| Regulates temperature — cool in heat, warm in cool | ✓ | ✕ | ✕ |
| Wicks sweat without the clammy, plastic feel | ✓ | partly | ✕ |
| No polyester or nylon | ✓ | ✕ | ✓ |
| Lets skin breathe | ✓ | ✕ | partly |
| Soft and non-itchy on skin | ✓ | ✓ | ✓ |
Overall rating: 5.0 / 5 from 5 reviews.
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"I do high impact training, so need a supportive bra. I was worried this wouldn't cut it, or fit correctly, but it kept the girls in their place and fit snuggly (I ordered a 10 - my bra size is 12DD). It looked and felt amazing too. And the best part is I can keep it on for my post-gym sauna (plastic free)! Can't wait to buy some more colours!"
"I bought this for running, however it's not quite supportive enough to wear on its own - I put another crop over the top for support and that worked well. It's comfortable enough to wear all day and doesn't overheat or get itchy. I bought my usual size and found it slightly roomy, so size down if you want a more compressive fit. Ran 8k in it on a hot day and it didn't get smelly - pretty amazing really!"
"This has become the item I gravitate towards in my wardrobe, I don’t wanna wear anything else because of how soft and comfortable this is while still allowing me to stay active! Obsessed with the feel of it. The full coverage is great for at the gym and as a top in summer, I love the padding also!"
"I bought the cocoa straight leg leggings, fit T and the sport bra. Fit was AMAZING. CUT AND QUALITY. I loved it. Not too stretchy so the elastine is low which is good. Haven’t tried to workout wearing them but I can’t wait to comeback for the review again. I have a suggestion if Estroni team can create more designs and colors. 💌"
"This natural fabric feels divine on. I like the coverage on these and thicker straps. Feels amazing during workouts and comfy and breathable enough I don't take them off for the rest of the day."
