Women Runners
Having the right running kit is now a given - you wouldn’t run a marathon in a pair of flip-flops. And yet many women are neglecting to support their breasts properly with the right kind of sports bra. In the first of our women’s product specials, Shock Absorber reveals why it pays to get your sports bra choice right.
Like women’s shoes and clothing (see our reviews that follow), the science behind sports bras has come on leaps and bounds in recent years. Specialist bra manufacturers have worked hard to increase the levels of support offered by their garments to prevent women from damaging their breasts during running.
And yet it’s something of a surprise to find out that many women still eschew a decent sports bra in favour of an everyday variety or, sometimes, nothing at all!
Research carried out by the Shock Absorber Sports Institute (SASI) at Portsmouth University found that the prospect of irreversible breast sag faces the 9.5 million British women, out of the 12 million currently taking regular exercise, who do not protect their breasts properly.
During exercise, research has shown that breasts move in a three dimensional movement, going up and down, in and out and side to side. With the average 36C breast weighing between 250-300grams, this movement puts great strain on the breast’s fragile support structure, which comprises only the outer skin and a connective tissue known as the Cooper’s ligament. Breast movement can cause the Cooper’s ligaments to stretch and lead to irreversible damage to the breasts.
Wearing a regular T-shirt bra during exercise reduces bounce by an average of 38 per cent - however it has been found that women fitted with a Shock Absorber sports bra reduces breast bounce by up to 74 per cent.
The appliance of bra science
While previous statistics had found that 73% of women in the UK who exercise regularly do not wear sports bras, the Shock Absorber Breast Movement Study was commissioned to further the understanding of the effect of exercise on the breast, and covered women running at speeds of up to 22kph and up to G cup.
What the Shock Absorber study monitored
* Sizes up to 36G
* 5 strides at each speed for all subjects, in all conditions
* 3D movement – vertical, side to side, and forwards and backwardsHow movement was tracked and analysed
Movement was tracked using four infra-red cameras. Recordings were then taken during three activities: static, jumping jacks and on a ramped treadmill. A comfort level was also obtained for each activity.
The Results
The results showed that wearing a Shock Absorber sports bra could reduce bounce by up to 74%. This has proven to be as much as twice as effective at minimising breast movement as a ‘normal’ bra.
3D bounce increases rapidly during the transition phase from walking to running, then levels off. The implication of this result is that you need a sports bra just as much at
lower running speeds than high speeds.
The detail
Dr Joanna Scurr, an independent head of biomechanics carried out the scientific study into the differing effects of wearing sports bras on three-dimensional breast movement during physical exercise.
Dr Scurr and her team physically tested 60+ women, ranging from A to G cup with no surgical implants. Subjects were asked to take part in treadmill running tests, to monitor levels of bounce with and without the support of a sports bra.
To expand on previous studies, Dr Scurr widened the testing boundaries by monitoring women on the running machine at up to 22 km/hour and women with breasts as large as a G cup. During testing subjects had relative markers attached to the nipple and the collarbone on both sides of their body.
Three-dimensional movement of these markers was tracked using 4 infrared cameras positioned around a treadmill.
The test began at 5kph and increased by 1 kph until the subject was performing at their maximum speed. This was repeated with the subject wearing a normal bra (brand leaders most popular everyday bra) and up to 9 Shock Absorber sports bras (depending on cup size).
Results showed that during treadmill running breast movement occurs in three dimensions from the front it follows a figure-of-eight patters (see figure 1). Figure 1. Example trace of nipple and collarbone markers across sports bra condition and no bra condition for G cup subject.
Figure 1 shows a comparison of breast movement viewed from the front in a Shock Absorber sports bra (on the left) and without a bra (on the right). The body (collarbone reference markers) is moving to the same extent; however without a bra breast movement is dramatically increased. The pattern of breast movement is also different in the no-bra condition, no longer following a figure-of-eight pattern, but following more of a pendulous motion. Without a bra a woman’s breast moves on average 9cm while running.
“Bounce-o-meter” from www.shockabsorber.co.uk which visually demonstrates the differences between wearing no bra, an ordinary bra and a Shock Absorber sports bra.
Table 1: 3D breast movement (in cm) without wearing a bra during three levels of activity
Cup Size |
A CUP |
B CUP |
C CUP |
D CUP |
DD CUP |
E CUP |
F CUP |
FF CUP |
G CUP |
AVERAGE CUP |
Gentle activity (walking at 5-6 kph) |
1.89 cm |
2.92 cm |
2.27 cm |
2.97 cm |
4.88 cm |
3.58 cm |
4.87 cm |
5.49 cm |
6.22 cm |
3.9 cm |
High activity (jogging at 7-9 kph) |
2.45 cm |
4.39 cm |
3.95 cm |
4.37 cm |
9.04 cm |
7.16 cm |
8.06 cm* |
8.00 cm* |
9.07 cm |
6.28 cm |
Extreme activity (Max running speed >9kph) |
4.03 cm |
5.98 cm |
6.06 cm |
6.82 cm |
10.10 cm |
10.25 cm |
11.53 cm |
12.82 cm* |
14.14 cm |
9.08 cm |
*Interpolated data
Without a bra the breast is capable of moving from 1.89cm during gentle activity to 14.14cm during extreme activity. On average the breast moves 9.08cm during running.
Figure 2: 3D breast movement (in cm) during treadmill running with no bra, for all cup sizes (cup sizes F and FF are interpolate).
It should also be noted that the percentage bounce reduction in a Shock Absorber bra was just as significant in the A cups (59%) as it was in the DD cup sizes (63%) during extreme activity. This suggests that Shock Absorber sports bras are equally as effective for all cup sizes.
