Is this sports bra supportive enough for large breasts?

Yes, absolutely. Specially engineered for C to I cups, the ComfyArc is designed to be the best sports bra for large breasts seeking a bulk-free fit. It utilizes a highly supportive underwire system and a reinforced mesh structure that lifts, separates, and anchors your chest. This effectively eliminates bounce and the dreaded "uniboob" effect during medium-impact activities like cycling, power walking, and weight training.

What does "outside underwire" mean, and will it poke my ribs?

An outside underwire construction is our innovative solution to wire chafing. Instead of placing the wire inside the cup where it rubs against your body, we placed it on the exterior. This friction-free design prevents the wire from directly contacting your skin, completely eliminating poking, digging, and irritation, while still delivering the heavy-duty lift of a traditional underwire sports bra.

Since it is an unlined sports bra, will my nipples show through?

The ComfyArc is intentionally unpadded to keep you cool and reduce bulk. However, we understand that show-through is a common concern with unlined activewear. That is why we include complimentary nipple covers and modesty pads with every purchase. You can enjoy the lightweight, breathable feel of an unlined bra with the option for complete coverage whenever you need it.

Is this racerback sports bra hard to take off after a sweaty workout?

Not at all! We designed this bra to completely eliminate the post-workout struggle. Unlike traditional pullover sports bras that get stuck to your sweaty skin, our racerback sports bra features a fully adjustable, multi-row hook-and-eye back closure and adjustable shoulder straps. This allows you to put it on and take it off in seconds—no locker room wrestling required.

Will this bra keep me cool if I sweat a lot?

Yes. If you struggle with heat trapped by thick foam pads, this is the solution. Crafted from silky, moisture-wicking fabric, it features a targeted power mesh cooling zone on the racerback. This highly breathable mesh sports bra design instantly releases trapped heat and maximizes airflow, ensuring you stay fresh, dry, and comfortable all day long.

HSIA Athea Hybrid Active Vibe Soft Support Non-padded Unlined Full Coverage Wide Strap Outside Underwire Sports Bra - HSIA

New arrival 20% off

ComfyArc Unlined Outside Underwire Racerback Sports Bra

$39.99 $49.99

9 reviews

By HSIA

Delivery: Free shipping for orders over $50 USD

Our 30-Day Fit Guarantee

We stand behind our products. If you don’t love it, exchanges and returns are FREE for 30 days.

Size & Fit

Best For: C to I cups. Highly recommended for medium-impact activities like cycling, weight training, power walking, and yoga, or for women seeking a highly supportive, unpadded everyday bra.

Smart Custom Sizing: The back closures scale intelligently to match your cup and band size, ensuring the band stays firmly anchored without riding up or digging in.

Materials & Care

Fabric:
Cups & Side Wings: 64% Nylon, 36% Spandex (Silky, flexible blend).
Back Lining: 74% Nylon, 26% Spandex. Upper Racerback Mesh: 57% Nylon, 43% Spandex.

Care Instructions: Hand wash in cold water or use a delicate cycle in a lingerie bag to preserve the high-performance elasticity and vibrant colors.

Product Details

Engineered for the woman who moves. Specially designed for fuller figures (C-I cups), the ComfyArc Unlined Sports Bra has earned its reputation as the best sports bra for large breasts. It proves that you don't need thick, suffocating foam to get the dependable, bounce-free support you crave.

We completely reimagined the traditional sports bra to eliminate the post-workout struggle and chafing. Featuring an innovative outside-underwire construction and a fully adjustable hook-and-eye closure, you can finally say goodbye to wire poking and the frustration of peeling off a tight, sweaty pullover bra. Crafted from premium, high-stretch moisture-wicking fabric, this racerback sports bra delivers a bulk-free, cooling fit. With its vibrant colorblock design and complimentary modesty accessories, you¡¯ll feel fierce, fresh, and fully supported from the weight room to your weekend cycling route.

Woman lifting dumbbells wearing a low to medium impact sports bra, showcasing four vibrant color options for a supportive, bounce-free workout.

Detailed view of the mesh racerback sports bra highlighting underwire support for medium coverage, a breathable cooling back design, and fully adjustable straps for a custom fit.

Close-up of the unlined sports bra design showing the friction-free external underwire construction and complimentary nipple covers and pads for modesty.

Four diverse women standing together modeling the best sports bra for large breasts in black, light purple, dark blue, and light beige.

A versatile underwire sports bra perfect for all-day wear and all scenes, providing maximum comfort for fitness training, spinning bike workouts, commuting, and leisure.

HSIA Athea Hybrid Active Vibe Soft Support Non-padded Unlined Full Coverage Wide Strap Outside Underwire Sports Bra

Why Your Curves Will Love It:

Friction-Free Outside Underwire: We flipped the script! The underwire is innovatively placed on the outside of the cups. This genius design makes it the ultimate underwire sports bra, preventing the wire from directly contacting your skin and completely eliminating digging or irritation while delivering heavy-duty lift and separation.
Modesty on Your Terms (Bonus Included): Love the cooling feel of an unlined bra but worry about show-through? We've got you covered. Every ComfyArc bra comes with complimentary nipple covers and modesty pads, giving you the flexibility and confidence to wear it exactly how you want.
Bulk-Free Cooling Comfort: Skip the heavy, sweat-absorbing padding. Our single-layer cups (64% Nylon, 36% Spandex) are incredibly soft, flexible, and lightweight, making this the ideal unpadded mesh sports bra to allow your skin to breathe during intense training.
Targeted Mesh Ventilation: The sporty back isn't just for unrestricted shoulder movement. Rated by our wearers as the best racer back bra for large breasts, it features a specialized, high-stretch power mesh that acts as a targeted cooling zone to instantly release trapped heat and maximize airflow.
Easy On/Off Custom Fit: No more locker room wrestling matches. Fully adjustable shoulder straps and a multi-row hook-and-eye back closure ensure a customized, secure fit for a bigger chest¡ªgoing on and coming off in seconds.
Vibrant Colorblock Aesthetics: Who says supportive has to be boring? The energetic color-contrast design brings a bold, dynamic edge to your activewear wardrobe, making it perfect to wear solo or layered under a tank.

Shipping & Returns

Handling Time
In general case, please allow us to take up to 2 business days to prepare the package.

Shipping Methods

Countries	Shipping Options	Delivery Time (Business Days)	Orders $50+USD (Include $50 USD)	Orders less than $50 (USD)
United States	Standard Shipping	5-9 Days	Free	$6.99 USD
Japan	International Shipping	5-9 Days	Free	¥1,100 JPY
Canada	International Shipping	5-12 Days	Free	$10.00 CAD
United Kingdom	International Shipping	6-10 Days	Free	£6.00 GBP
Switzerland	International Shipping	6-12 Days	Free	CHF 6.00
Germany, Spain, France, Italy	International Shipping	6-12 Days	Free	€6.95 EUR
Australia	International Shipping	10-15 Days	Free	$11.00 AUD
Saudi Arabia	International Shipping	8-12 Days	Free	SAR27.00

Free Shipping Eligibility
Enjoy free standard shipping on all HSIA intimate apparel orders totaling $50 USD or more.

International Orders

For customers in countries outside the U.S. purchasing with non-USD currencies:

Order values must convert to $50 USD or more to qualify for free shipping
Exchange rates are calculated based on the daily international exchange rate (reference table provided for estimation purposes only)

Standard Shipping Fees

Orders below the $50 USD threshold:

$6.99 USD shipping fee for U.S. addresses
International shipping fees calculated at checkout based on converted USD value

Delivery Restrictions

We currently cannot ship to:

APO/FPO addresses
U.S. territories: Puerto Rico, Guam, U.S. Virgin Islands
U.S. states: Alaska, Hawaii

SHIPMENT TRACKING
You will be notified by email automatically with the tracking number and tracking way once your order is marked as fulfillment status. Or you can directly reach out to us via contact form.

WRONG ADDRESS
We know mistakes do happen! Please email us immediately! We can only fix this for you if the order has not been shipped out yet.

LOST OR STOLEN PACKAGES
If you believe that your package was lost or stolen, please directly reach out to us via contact form.

DUTIES AND TAXES
Customers shall be responsible for customs clearance, Duty and Tax. All international packages may be subject to duties and taxes. The limits for duty-free packages are established by your local customs authorities. Please check your local customs website for more information.

SKU: FBD0542BCG32D

View details

ComfyArc Unlined Outside Underwire Racerback Sports Bra

Black / 32 / D – Change

Frequently Asked Questions

What size am I? How do I measure my bra size?

Fit and sizing can be tricky when shopping online. We totally feel you! We’ve tried our best to create a size calculator, which you can find on each product page. Also, you can visit our BRA CALCULATOR page.

What are my shipping options (and prices)?

For all US orders over $50, you can choose this option:

Standard Shipping: Free (5-12 business days)

Currently, we offer one option for all US orders less than $50:

Standard Shipping: $6.99 (5-12 business days)

NOTE: We currently UNABLE ship to APO/FPO addresses. U.S. Protectorates/Territories, Puerto Rico, Guam, Alaska, Hawaii and Virgin Islands.

OUTSIDE the United States :

We only offer International Shipping. If you order less than $50, the fee will be $6.99.*

The shipping time varies from region to region. Please see the exact shipping cost and delivery time on the actual payment page.

* The shipping fee may vary or be FREE while the website is going with a Shipping Promotion.

How do I track my order?

After you placed your order, we sent you a confirmation email / text message with your purchase (depending on which of the two you chose to give us during checkout).

Once your order has shipped and is on its way to you, we'll send a confirmation email with the tracking number, so you can follow its progress. Didn't receive confirmation? Please click this TRACKING LINK. Contact our customer service service@hsialife.com

Can I cancel or modify (all or part of) my order after it is placed?

Please contact us at service@hsialife.com during 24 hours to modify or cancel the order.

*Since we start to process your order shortly after it is placed, in many cases it is not possible to change or modify. But we will do our best to accommodate any changes. Please understand however that this is not always ‘possible’. If you are unable to cancel within that time frame, you may return or exchange your order after you receive it.

Can I exchange or return the product?

Please go to RETURNS & EXCHANGES for more details.

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ComfyArc Unlined Outside Underwire Racerback Sports Bra

ComfyArc Unlined Outside Underwire Racerback Sports Bra

Frequently Asked Questions