Cooper’s ligaments are like elastic bands – once they are stretched it is impossible to reverse this over-stretching. With the average 36C breast weighing 300 grams, uncontrolled movement during exercise puts great strain on this fragile support structure.

What’s wrong with women wearing their normal bra to exercise in? The University of Portsmouth carried out research in 2005 and 2009, which looked into breast bounce while treadmill running up to 20km/hour in subjects ranging from an A-G cup. It compared bounce in women with no bra, a normal bra and a specialist sports bra. (6)

Retro reflective markers were positioned on the body and 3D movement was tracked using four infrared cameras (shown by the red markers in the image opposite.)

The results showed that on average, the breast moves by 9cms when running without a bra. At the most extreme end, a G cup can move up to 14cms whilst exercising and even an A cup can move up to 4cms! This movement is reduced by up to 78% when wearing a specialist sports bra, whereas wearing a normal bra only reduces this bounce by up to 38%.

So how is a sports bra so much better than a normal bra? Sports bras are specifically designed to offer added comfort and support for women whilst they are exercising. The key benefits are that they offer protection for the key pressure points and hotspots identified during sport which can be seen in the diagram opposite.

Unlike a normal bra, specialist sports bras are made with special sports performance materials which enhance the wearers comfort whilst exercising. Breathable fabrics allow air to circulate between and under the breast, minimising discomfort and, in some cases, rubbing. The fabrics and fastenings used in sports bras also tend to be stronger and more durable than in normal bras. Finally abrasion resistant fabric is used to prolong the shape and support structure of the bra.

How do you know whether a sports bra is doing what it is supposed to? Whilst exercising, the breasts should not move independently of the body e.g. when doing a 5k run your breasts should not bounce any further than you do.

To ensure that a sports bra is doing its job; the bra must fit perfectly to the body and offer the correct type of support for the level or type of activity being done: l A compression bra gives support by pressing the breast against the chest. These types of bra are ideal for low impact sports like

“To ensure that a sports bra is doing its job; the bra must fit perfectly to the body and offer the correct type of support for the level or type of activity being done.” 16

Cross-sectional study of the breast Clavicle

Cooper’s ligaments

Pectoralis minor

Pectoralis major

Rib

Retro reflective markers help track breast movement

yoga or floor work. They tend to be in the style of a crop top with a racer back.

l An encapsulation bra supports and shapes each breast independently and is ideal for higher impact sports such as running or aerobics.

l Finally some bras offer a combination style of support, utilising both compression and encapsulation making them ideal for most exercise.

A poorly fitting sports bra will provide no support! Finally, wearing a badly fitted sports bra can be just as bad as not wearing one at all. Experts recommend that women are professionally fitted on a regular basis as breast shape and size can fluctuate constantly. Age, changes in weight, pregnancy and monthly cycles can all affect women’s breasts. However, a huge 80 - 85% of women are wearing the wrong sized bra, that’s four out of every five women! To ensure that a sports bra fits correctly, there are a few key things to look out for.

The underband should be firm and level the whole way round. If it rides up at the back it means that the band is too big. If you pull the band away from the body, there should only be a one or two inch give. The band should feel neither too loose nor too tight. The cups should contain the whole of the breast with no creases or cleavage on show. If there is any gaping or wrinkling of the

The REPS Journal 2013;26(January):15-17