What is appropriate breast support?
Breast movement and breast strain
- Breasts move relative to the chest wall when women participate in physical activity.
- Breast motion is exacerbated during activities where the torso moves up and down (jumping and running).
- Excessive breast motion = exercise-induced breast pain = negatively affects occupational performance.
- Wearing appropriate external breast support (such as a sports bra) typically recommended.
- Breast injuries and pain still common, despite extensive biomechanical research over the past 15 years to improve sports bra designs = more research needed.
Breast tissue is not like other tissues in the human body - it doesn’t have any muscle or bone within it.
The complexity of breast motion can be seen in this video. It is taken from a 34DD (UK size) woman running on a treadmill whilst bare-breasted, so not wearing any external breast support. And you can see here, the breast doesn’t just move up and down, it moves in all directions and even deforms and is manipulated by the movement it is going through. There is an array of markers on the breast to try and track this motion.
There is a time-lag that occurs between the body and the breast, the body moves upwards followed by the breast. The breast then reaches its highest point just as the body starts to move downwards, which then pulls the breast downwards which creates a real strain on that breast tissue. And that is essentially what sports bras are trying to limit, that time-lag, to make the movement of the breast more in sync with the movement of the body.
Bra types available
There are three basic types of sports bra – compression, encapsulation and combination.
They each support the breasts in a different way:
Compression sports bra (or crop top)
- A compression sports bra, also known as a crop top style, aims to compress the breasts closer to the chest in order to reduce breast movement.
- Moves the centre of mass of the breasts closer to the body, which reduces what we call in biomechanics, the moment (force x distance) of the breast.
- Usually one piece of strong, elastic material
- Stretches when putting on and taking off – decreases lifespan of bra
- Research promotes use of this style for smaller-breasted (<D cup) women only
Encapsulation sports bra
- An encapsulation style sports bra separates and supports each breast individually halving the mass.
- They are more of a sturdy construction and many tend to use underwire to create that separation to form two individual cups.
- Research promotes use of this style for larger-breasted (>D cup) women to reduce movement and discomfort.
Combination sports bra
- There are bras on the market that incorporate both an encapsulation and a compression element. There tends to be encapsulating cups but with an external layer of fabric spanning across them to create compression.
- Can reduce exercise-induced breast pain by minimising ‘breast slap’ - simultaneously elevating and compressing the breasts.
It is not clear which sports bra style is best, although it seems that different sports bra styles suit different functions and breast sizes, therefore having a variety of styles on the market is useful.
Considerations for work
Wearing body armour causes a level of discomfort for female officers and a restriction in the capability to perform actions, especially running and self-defence, which are the most physical activities performed. Wearing an appropriate bra may be critical for comfort when worn with body armour.
Research has shown that 71% of female police officers are wearing an underwired everyday bra, with the next most common bra being a sports bra (17%). However, research showed that when officers were fitted for a new sports bra and underwired bra to wear for duty, over 70% of officers stated that they found the sports bra was more comfortable. In addition, wearing a sports bra meant that various actions were easier to perform, and they would most likely wear a sports bra in future under their body armour.
Washing and wearing of sports bras
So how often should you change your sports bra? What is the lifespan of a sports bra? A lot of that comes down to the washing and wearing of the garment as laundering affects the mechanical properties of some sports bra materials. After 25 washes of a sports bra the support it provides will start to reduce, although it is likely to remain comfortable. As a rule of thumb, when you change your trainers you should consider changing your sports bra!