How to Stretch Out a Sports Bra

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Sports bras are specifically designed to be well-fitted to provide enhanced support. Thus, your sports bra will feel tighter than your regular, everyday one. However, if the sports bra feels too tight to the point of being uncomfortable, you should make it loose.

How to Stretch Out a Sports Bra

Stretching out a sports bra is a common practice. It is a useful technique when the current sports bra feels too snug, yet going up a size is not an option as it will be too loose. In this case, you can loosen up your sports bra, so it feels more comfortable.

A woman in a sports bra with a camouflage design wearing black leggings using a blue dumbbell to exercise inside a room

Ways to Stretch Out a Cotton Sports Bra

Step 1Fill a bucket with one liter of hot water
Step 2Pour one tablespoon of baby shampoo
Step 3Stir until you form a homogenous solution
Step 4Submerge the sports bra in the solution for 30 minutes
Step 5Take out the sports bra and squeeze it gently to drain the excess water
Step 6Place the sports bra between the folds of a big, dry towel and gently squeeze it further
Step 7Pull the sports bra with your hands to stretch it out until you get the desired size
Step 8Rinse your sports bra with lukewarm water to remove the shampoo
Step 9Stretch it one last time before drying it

Ways to Stretch Out a Polyester Sports Bra

Step 1Wash the sports bra on a high heat cycle for more than 30 minutes
Step 2Hang to dry immediately
Step 3Use pegs to hang weights from the sports bra to stretch it out
Step 4Alternatively, use an iron with a steamer to dry out the sports bra while stretching it
Step 5Dry out the bra
Step 6Repeat the process multiple times until you are satisfied with the fit

How to Stretch Out a Cotton Sports Bra

Sports bras made with cotton are breathable and great for low-impact workouts. They are not suitable for a HIIT workout, where you tend to sweat a lot as the cotton fibers are unable to wick away the sweat and can end up feeling soggy.

If you own a cotton bra that is too tight, here is how you can make it fit well:

  1. Fill a bucket or sink with around 1 liter of lukewarm water.
  2. Pour about 1 tablespoon of hair conditioner, mild detergent, or baby shampoo into the water.
  3. Stir the water until the conditioner or shampoo is mixed well to form a homogenous solution.
  4. Submerge your sports bra completely in the solution and allow it to soak for 30 minutes.
  5. Take out the sports bra and squeeze it gently to drain the excess water.
  6. Place the sports bra between the folds of a big, dry towel and gently squeeze it further so the towel absorbs as much water as possible.
  7. Pull the bra with your hands to stretch it out until you get the desired size. Use another bra as a gauge to determine the perfect size.
  8. Rinse your bra with warm water to remove the conditioner or shampoo. Do not use cold water.
  9. Stretch it one last time before it gets dry completely while holding it in its stretched-out dimensions.

How to Stretch Out a Polyester Sports Bra

Sports bras are usually made of polyester, a moisture-wicking, synthetic fabric. Consequently, it absorbs the sweat and allows it to evaporate in the air, leaving you feeling dry.

If your bra is tight and made up of polyester, here is how you can fix it:

  1. Wash your bra on a high-heat cycle for more than 30 minutes.
  2. Hang it to dry immediately on a clothing line while still wet and warm.
  3. Use pegs to hang weights from the bra while it dries to help you stretch it out.
  4. Alternatively, you can also use an iron box with a steamer to dry out the bra while stretching it with your hands.
  5. Dry out the bra completely before trying it out to see if it fits right.
  6. Repeat the process multiple times until it fit properly.

How to Determine the Proper Sports Bra Fit?

An athletic bra restricts excessive movement of your breasts and keeps them firmly in place while you exercise. Without proper encapsulation, you might experience soreness and even lasting damage to the connective breast tissues that support your breasts.

Graphic image of a blue bra that explains that sports bras are ideally made from moisture wicking material with wide straps

However, the bra should be just tight enough to perform its function and to be able to be worn comfortably as your top. If it is too restraining and compressive, it can cause:

  • Your ribs hurt where your band sits or the band feels constrictive
  • Extreme chafing and rashes
  • Chest pains due to high compression of the bust
  • Visible imprints on the skin from the bra seams

Therefore, to ensure that your bra fits you perfectly:

Check the Band

Just like with normal bras, the band is responsible for most of the support offered by sports bras. If it is not the correct size, your bra will be impractical. Hence, try on the bra and see how the band feels. It should not dig into your skin yet still, feel snug.

It should also sit at a level around your body and not ride up your back, as this indicates a loose band. In addition, you should be able to fit a finger under the waistband firmly and comfortably. Finally, it should not feel like the band will climb up your breasts or like you cannot breathe.

Woman in a black sports bra and gray leggings exercising using a dumbbell outside the house

Check the Straps

The straps hold the bra cups in place, so they should not slip down or dig into your shoulders. To check that the straps are the correct size, try to fit two fingers between the strap and the shoulder. If you are able to do this comfortably, the strap is perfectly adjusted.

However, if you struggle to do it with one bra or can fit in more than two fingers, the strap is too tight or too loose simultaneously. Moreover, lift up your arms above your head, and if the band rides up, it is often because the bra is too big.

Check the Cups

The cups of athletic bras are designed to engulf the breasts and hold them in place. If the cups are too big, there will be gaps between the skin and the stretch fabric. All the extra room means that your bust is not well-supported.

On the other hand, if your cups are too small, the breast tissues will spill out from the edges. You will also feel breathless sooner, as the cups restrict the airflow to your lungs. Finally, the underwire of the bra will not lay flat against the rib cage and pinch or dig in your lower breast tissues.

Important tip: Before buying a sports bra, do a few jump squats, swing your arms around, twist from side to side, and jog around while wearing the bra. See how the fit feels, how easily you can put it on and take it off, and how much movement you experience around the bust region. Look for another cup size if you are ill at ease.

Related Questions

Do Sports Bras Stretch Out With Wear?

Sports bras would eventually stretch out as you wear it. However, this may depend on the material and how often you use it.

How Long Does It Take for Sports Bras to Stretch Out?

It may take about two weeks for sports bras to stretch out. Particularly for a newly bought bra, it could take weeks to adjust to your physique.

Why Do My New Sports Bras Feel Tight?

Your new bra feels tight because it’s normal for sports bras to have a snug fit at first. With the steps mentioned above, you can stretch out the band of your tight sports bra for a more comfortable fit.

How to Fold a Sports Bra [& What to Avoid!]


Stretching out a sports bra is the perfect solution for a bra that is slightly too snug. While these sports bras do loosen up over time after multiple washes, you should not suffer through the pain of a constrictive athletic bra. Instead, choose sports bras with thicker material and take the necessary steps according to the bra fabric to make it fit seamlessly.


Allena is the Founder and Editor of The Better Fit, a platform dedicated to empowering women with practical advice on bras and fitness, inspired by her own revelation of the widespread issue of incorrect bra sizing. Her expertise and tips have been recognized by major publications such as Cosmopolitan, Better Homes & Gardens, Insider, and NBC, making her a trusted voice in women's wellness and lifestyle.