This blog will cover a piece of equipment that’s just as crucial as having the right shoes suited to your sport; something that can either make or break your performance in the seconds that matter the most. What’s more, when this piece of equipment is ignored or underestimated (like it is in many cases across the world), it can affect not only the immediate performance but also the long-term health of the athlete, so much so that top notch athletes like Simona Halep and Rosie Galligan chose surgery to mitigate the negative experiences they had from lacking this crucial piece that we call sports bras. Many of you would have dropped out just from hearing the word alone, and that’s the mission at Tigers Eye: redefining how the world thinks about sports bras. Because they’re not just underwear, they are a crucial part of equipment and the science around it will blow your mind.
What are sports bras
Before we jump into all the crazy science that proves just how important sports bras are for performance, let’s get to know what they are first.
Sports bras are sporting equipment with the primary function of breast support. The first sports bra was invented in 1977 (Jogbra) to help women jog without breast movement; more about why that matters, in the next section. This first sports bra consisted of jock straps and cups, as seen in the picture below.
Polly Smith, Linda Lindahl, and Hinda Miller create the Jogbra in 1977
The problem? Despite evolution in moisture-wicking fabrics, the invention of the Research Group in Breast Health (RGBH) in 2005 and many major breakthroughs in technology, the design of the sports bra has relatively been the same since it’s invention in 1977, unlike other equipment like shoes.
Why sports bras matter: the science
Shoes are designed around the demands of specific sports. In running, they influence gait, stride length, impact absorption, and how force travels through the foot and up the body. The right shoe can improve efficiency, reduce fatigue, and help protect joints by guiding movement and managing load. While shoes play a crucial role in performance and injury prevention, their impact is largely focused on the feet and lower limbs.
Sports bras, however, have been shown to influence whole-body biomechanics. Inadequate support can affect posture and upper-body stability, alter running mechanics such as stride length and trunk motion, and increase loading on the lower limbs. It can also restrict breathing capacity and increase upper-body muscle activation as the body works to control excess breast movement. The result is often earlier onset of fatigue, discomfort, and reduced performance during high-impact activity.
There have been numerous studies come out in the last two decades, mainly from the University of Portsmouth RGBH but not only, that found the following:
→ Running without proper breast support decreases stride length by 4cm, adding up to a mile over the distance of a marathon course – therefore athletes cover less ground.
→ Bigger breasts need more support: there’s a difference of roughly 5-9 minutes between cups, meaning if you have a set of identical fitness level twins, one with A cups and one with DD cup size, the twin with the smaller breasts will finish about 35 minutes ahead (Brown & Scurr, 2016) – based on breast volume alone.
→ Breasts move in many different directions including up and down, side to side and figure 8 (see below).
Breast movement trajectories of body (solid line) and breast (dotted line) with sports bra in one stride of running in the medial/lateral direction
Lack of sufficient breast support decreases oxygen intake and causes early upper body muscle fatigue
Without proper support, there’s an increase in ground reaction forces, meaning athletes hit the floor harder on landing, which increases their risk of injury including ACL
→ Similarly, 72% of active women also report breast pain during exercise
→ Breast pain and movement cause discomfort which is distracting
Because sports bras haven’t been getting the same attention, investment and respect as shoes, there has been a lack of education and knowledge in understanding how sports bras work and what makes a good sports bra fit for athletes. Despite being plenty of options out there, there’s a clear trend:
→ High-support sports bras are not comfortable at all; they are too tight, they restrict breathing and full range of movement, causing nerve-impingement damage and rib cage pain
→ Comfortable sports bras lack support, allow painful breast movement which is distracting and affects performance, decreases agility and stride, and causes irreversible breast tissue damage which leads to early sagging
Many established sportswear brands have invested heavily in research and innovation, yet creating a sports bra that delivers both high levels of support and long-term comfort across a full range of breast sizes remains a complex challenge. One possible reason is that achieving this balance often requires advanced materials, construction, and education around fit and use, all of which increase cost. As a result, many mainstream sports bras are designed to meet the needs of the broadest possible audience, leading to compromises. A bra may excel in one area, such as cushioned straps to reduce shoulder pressure, while offering less in others, like fully moulded or individually supportive cup structures.
Sports bras on the market aren’t good enough
If all that wasn’t enough to demonstrate that sports bras are more than just underwear, some top athletes have described their experience undergoing breast reduction surgery after years of inadequate support affecting their comfort and performance, and threatening their careers.
Simona Halep went from 34DD to 34C at age 17
Rosie Galligan went from 32HH to 32DD at 20 years old
If truly supportive sports bras without compromise had existed, both athletes might have had the support they needed. Having breasts wouldn’t have been a barrier to their careers, and surgery may never have been necessary.
A balanced sports bra – finally?
It has taken personal pain and experience to drive a woman to finally create the product all women are begging for all around the world, including athletes. This sports bra by Tigers Eye is the perfect mix of compression and encapsulation, research-informed features tested at the University of Portsmouth’s RGBH which was proven to provide both high support and a high level of comfort.
This bra was tested against the biggest brands in the world and it came out first, but Tigers Eye didn’t stop there. It was further field tested by athletes, active-duty US Marines and in active combat on the Ukrainian frontline – because if a bra can withstand such harsh environments, training and performance is a freeze.
Tigers Eye, although specialised for servicewomen, are loved amongst many sporting communities from running to football, horse riding and rugby. Let’s hear it from the Henley Hawks Women’s Rugby Team how this sports bra works for them.
Tigers Eye is closely monitoring any impact on performance for the Henley Hawks team. We’re very excited to be sharing our findings and to continue to gather feedback from the Henley Hawks Women’s Rugby team as they train and play in our bras.
Dear sports teams and athletes,
If you take anything away from this blog let it be that sports bras belong in the essential kit. They are not underwear, they are not taboo, but they certainly are something that needs to be talked about more, invested in and recognised for their crucial role in making or breaking women’s sporting performance. It can be the difference between first and second place, between gold and silver, and outstriding an opponent when needed the most.
Talk about sports bras with your teams, captains and coaches and ask for better solutions. They exist now.
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