Research has found that around 80% of women wear the wrong size sports bra. This might mean that you aren’t giving your breasts the right support, and this could impact your enjoyment and performance in a workout.

We talked to breast health expert Dr Nicola Brown from St Mary's University, Twickenham, London to find out how to get that perfect fitting sports bra.

Sports Bras

Breasts have limited natural support and, as a result, excessive breast movement can occur during physical activity. Not only can this cause major discomfort and pain, but it is also thought to put strain on the fragile supporting structures of the breasts, causing breasts to sag. Excessive breast movement (which can be 4-15 cm in a range of directions) can also cause pain, embarrassment and self-consciousness, and is often a barrier to exercise. A well-fitting sports bra is important to support the breasts and to allow women to exercise in greater comfort.

The Evidence            

There is evidence to show that wearing a well-fitted sports bra instead of an ‘everyday’ bra can impact movement patterns and physiological measures. For example, wearing a sports bra can reduce activity of the pectoral muscle by 55%, which may negatively affect muscular fatigue while running. Insufficient breast support can also change running profiles and increase the forces exerted through the leg – potentially increasing injury risk. The right sports bra can also reduce perceived exertion, allowing you to enjoy workouts and push a little bit harder.


Traditionally, sports bras are classified into two different types:

1)   Compression bras: these typically pull over your head and restrict breast movement by flattening the breasts against the chest wall

2)   Encapsulation bras: these use individual cups to surround and support each breast separately, similar to ‘everyday’ bras.

Like trainers, different bras will fit differently. You may need to try a few to find the best brand, model and size to suit you. When you try a sports bra on before you buy it, it is a good idea to jump around a bit in the fitting room to check that it’s giving you the support that you need.


It can be overwhelming and confusing to find the right-sized bra for you, especially as manufacturers have inconsistent sizing, and breasts can change size, shape and position throughout the menstrual cycle and throughout life. In fact, a large percentage of the population is reported to be wearing the wrong bra size.

Research has found that the traditional method of a tape measurement is actually unreliable – it overestimates the under band size 76% of the time and underestimates the cup size 84% of the time! Instead, there are some ‘best fit’ criteria to look for when trying on a bra to help you assess your own bra fit.

The Best Fit

1. The under band: this should be level all around the body. You don’t want it too tight so that it is uncomfortable, it affects your breathing, or that it makes flesh bulge over the band. The band should fit firmly around the chest.

2. The cups: people often wear cups that are too small, causing the breasts to spill out. If they are too big, the cup will hang away from the breasts. The breasts should be enclosed within the cups, with no bulging or gaping at the top or sides.

3. The shoulder straps: these should be adjusted to comfortably provide breast support without being too tight (digging into the skin), or too loose that they slip off your shoulders. You should be able to fit two stacked fingers comfortably between your shoulder and the strap.

4. The centre front: this should sit flat against your chest. If it doesn’t, your cup might be too small.

5. The underwire: if your bra has one, the underwire should follow the natural crease of the breasts and not rest on any breast tissue, including under your arms.

Following these steps will help you find the right sports bra for you!

Download FitrWoman for free:

App Store

Google Play

Follow us on: 




Do you have a question? Contact us now!

Contact Us

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.