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Fitness professionals are ideally positioned to offer advice to female clients about breast support and bra fit during exercise, writes Dr Deirdre McGhee.

When it comes to working out, many female clients appear to put a lot of thought into their workout gear, selecting moisture-wicking, chafe-resistant items in a dizzying array of stylishly breathable designs. But there is one area that all too often doesn’t receive this same attention to detail: the breasts – and more specifically, their support. As a fitness professional, you are well placed to offer guidance to clients on this topic – provided you feel confident to do so, and you believe your clients will be comfortable receiving advice from you.

Why do women need advice about breast support?

If the breasts are not supported sufficiently during exercise, they can move excessively, which can cause breast discomfort and embarrassment, particularly for those with larger breasts. Research has found that both of these issues are barriers to adolescent and adult females participating in physical activity. Adolescent females typically decrease their level of physical activity relative to childhood1 and age-matched boys2 with the onset of breast development. This decline extends into adulthood3, and hence negatively affects the level of physical activity and long-term health of nearly half of the population.

Biomechanical studies have found that as many as 56 per cent of women suffer from breast discomfort with exercise, particularly during exercise such as running and jumping. In fact, biomechanists have measured bare breast movement in the vertical plane as high as 12 cm4. This movement can be reduced by at least 50 per cent by wearing a well-fitted, high-support sports bra5. Unfortunately, research by Breast Research Australia, at the University of Wollongong, has found that most Australian women wear insufficient breast support during exercise relative to their bra size, age and level of physical activity 6, 7.

What is sufficient breast support?

Well-supported breasts should display minimal breast movement, without discomfort being incurred during exercise. The amount of breast support required is dependent on each woman’s age, bra size and level of physical activity8.


The breasts are primarily supported by the skin covering them. With age, the elasticity of the skin decreases and the breasts start to sag. As the level of support provided by the skin reduces with age, the level of support required by a sports bra increases.

Bra size

Larger breasts are heavier than smaller breasts. For example, a 10D breast is approximately 400ml, while a 16E is approximately 1400ml. Consequently, larger bra sizes require more support from a sports bra compared to smaller bra sizes9.

Different types of exercise

Different exercises produce different amounts of breast movement. Breast movement is greatest in exercises that involve more vertical movement of the body (e.g. horse riding compared to bike riding; jumping compared to walking) or movements involving rapid movement of the legs (e.g. running compared to walking). Activities that produce greater breast movement require greater breast support.

Guidelines: Factors affecting support
  • The level of breast support women need increases with their age (> 40 yrs) and bra size (> cup size DD).
  • Breast movement should be minimal during exercise. Women should observe their breast movement in a mirror during exercise to assess this. Where appropriate, fitness professionals can also pay attention to the breast movement of clients and recommend the need for greater breast support if required.
  • Breast discomfort should also be minimal. If women are experiencing breast discomfort during exercise, this can be relieved by increasing their level of breast support.


What is a high support bra?

High support bras for sport aim to limit breast movement. They come in two basic designs, sports bras and crop tops.

Sports bras

Sports bras (also known as encapsulating bras) support each breast in a separate cup and have fasteners to do them up at the back of the bra. Variations of underwire/soft cup and vertical straps/cross-over straps do not affect the level of support and are simply a matter of personal preference in terms of comfort and appearance. For any underwire bra, however, it is essential that it fits correctly.

Crop tops

Crop tops hold and compress the breasts as a single unit against the chest wall. Typically, crop tops do not have fasteners at the back and are put on by pulling them over the head. This can be difficult for some women, particularly those with shoulder limitations. Those who experience such problems should make the extra effort to locate crop tops that have fasteners at the back, as they are easier to get on.

Biomechanical studies have found that breast movement is generally less in sports bras compared to crop tops. Therefore, women with large breasts are usually recommended to wear a sports bra rather than a crop top. However, women with bra cup sizes greater than a DD+ are often encouraged to wear both a sports bra and a crop top simultaneously to gain sufficient support.

Guidelines: Features of high support bras
  • Cups: should cover the breasts completely using strong, supportive material (not lace/Lycra)
  • Band: should be made of strong elastic material, wide enough relative to the breast mass (A-D cup: 2 clips wide; D+: 3 clips wide)
  • Straps: must be wide and padded for comfort
    Front band: should sit flat against the breast bone (this may not be possible for females with breasts larger than an E cup)
  • Underwire or softcup: depends on the fit. The underwire must sit on the breast bone at the front and the ribs under the armpit,
  • NOT any breast tissue. The soft tissues (fat and gland) of the breast are not designed to tolerate the forces caused by underwire. If the underwire is sitting on breast tissue, a soft-cup version is more suitable.


What about bra fit?

In order for a bra to support the breast properly, it must also fit correctly. Research conducted by Breast Research Australia has found incorrect bra fit is a very common problem in both adolescent and adult Australian females, with 85 per cent of both groups found to be wearing ill-fitting bras5. Research has also found that Australian women do not usually use professional bra fitting services, commonly fitting themselves5. Therefore, any tips from fitness professionals to assist women with correct bra fit can be beneficial.

Another common breast support issue that can be raised by fitness professionals is wearing a bra beyond its ‘use by’ date. Once the elasticity of the bra band has decreased and the material starts to break down, the bra no longer provides sufficient support. So, like worn out sports shoes, a worn out bra should no longer be worn.

Guidelines: Correct bra fit
  • Band: does not ride up when moving the arms above the head (if it does, it is too big), and no flesh bulging over the top edge of the band (if so, it is too small)
  • Straps: not sliding off (too loose), and not digging in (too tight)
  • Cup: no wrinkles or gaps (too big), and no bulging of breasts over the top or sides of the cup (too small)
  • Underwire: sits on the ribs and the breast bone, not on any breast tissue (too small)
  • Front of band sits flat against the breast bone.


Free resources for fitness professionals
Sports Medicine Australia is a national multidisciplinary organisation committed to enhancing the health of all Australians through safe participation in sport and physical activity. It believes that breast support is such an important issue for women to maintain and increase their level of activity that, in conjunction with Breast Research Australia (BRA), it has developed a free resource Exercise and breast support. This pamphlet offers females of every age a simple, easy-to-read guide to help them choose a supportive, comfortable sports bra that fits correctly. It is a great resource for fitness professionals to use as an ice-breaker when raising the important but sensitive topic of breast support with clients. Copies can be accessed through the Sports Medicine Australia website BRA has also just launched a new app, Sports Bra, available on iTunes ($0.99c) to help women select the right support bra.


Guidelines: Features of high support bras
  1. Trost SG, Pate RR, Saunders R, Ward DS, Dowda M, Felton G. (1997). A prospective study of the determinants of physical activity in rural fifth-grade children. Preventive Medicine. 26: 257-263.
  2. Tammelin T, Ekelund U, Remes J, Nayha S. (2007). Physical activity and sedentary behaviours among Finnish youth. Medicine and Science in Sports and Exercise. 39(7): 1067-1074.
  3. Taylor WC, Blair SN, Cummings C, Wun CC, Malina RM. (1999). Childhood and adolescent physical activity patterns and adult activity. Medicine and Science in Sports and Exercise. 31(1): 118-123.
  4. Boschma ALC. (1994). Breast support for the active woman: Relationship to 3D kinematics of running [Masters]. Oregon: Oregon State University.
  5. Mason BR, Page KA, Fallon K. (1999). An analysis of movement and discomfort of the female breast during exercise and the effects of breast support in three cases. Journal of Science and Medicine in Sport. 2(2): 134-144.
  6. McGhee DE, Steele JR. (2010). Preventing musculoskeletal pain and promoting physical activity in females through correct bra fit. A cross-sectional study. Journal of Science and Medicine in Sport 13: 568-572
  7. McGhee DE, Steele JR, Munro BJ. (2010). Breast support education improves bra knowledge and bra wearing behaviour in young female athletes: A randomised controlled trial. Journal of Physiotherapy. 56(1): 19-24.
  8. McGhee DE, Steele JR, Munro BJ. (2008). Sports Bra Fitness. Breast Research Australia (BRA), Wollongong NSW.
  9. McGhee, DE & Steele, JR. (2011). Breast volume and bra size. International Journal of Clothing Science and Technology. 23(5): 351-360.


Dr Deirdre McGhee
Deirdre is a researcher for Breast Research Australia (BRA), a senior lecturer in exercise science at the University of Wollongong and an APA sports physiotherapist. She has extensive experience as a clinician, researcher and teacher in the area of breast support during exercise, aiming to empower women with knowledge on this topic to promote their level of physical activity. For more information contact

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