The ultimate guide to sports bras

Boobs are wonderful things. But during sport they can move around, bounce up and down... and hurt. Breasts have a 4cm range of movement during a walk and a 15cm range when running, according to the NHS, with the multi-directional swaying causing pain, embarrassment and eventually, sagging.

While high-impact sports like running clearly have the biggest bounce-factor, your breasts will move more than you do no matter what exercise you’re trying. Pounding out a 10k on the treadmill? The girls will have run the equivalent of a marathon.

It’s enough to put you off going to the gym altogether - and it does. A survey by Portsmouth University’s Research Group in Breast Health found breasts were the fourth biggest barrier to exercise for women after motivation, time and poor health.

Luckily, a high impact sports bra from Pour Moi can help. From underwired to non-wire, lightly padded to adjustable, our shock absorber bras can minimise the bounce and support the sensitive breast tissue to leave you feeling comfortable (and even sweat-free).

But what do you need to know before you buy? Our no-nonsense sports bra guide has everything you need to find your perfect fit.


The history of sports bras

Inventing women’s sports bras became something of a priority in the US back in the 1970s. The jogging craze was sweeping the nation, and normal bras were woefully inadequate to deal with all the impact. In fact the typical bra of the era was so unsuitable for running that the very first sports bra prototype wasn’t modelled on a bra at all. It was made by sewing two male jockstraps together.

The ‘jockstrap bra’ was made by female jogger, Lisa Lindahl and her seamstress friend Polly Smith, who patented their ‘Athletic Brassiere’ after they couldn’t find what they needed in the shops. Their original designs look very much like the high support sports bra we know and love today, with a cross-over back that stopped straps from slipping and a thick elastic band under the bust. It was made of an innovative (for the time) cotton/lycra blend and was seam-free and soft, to prevent chafing.

“I wanted it, so I assumed every woman wanted it,” Lindahl said. She was right, and their cross-back sports bra was a huge success, with the product selling out fast and second year sales worth $500,000. Today, the global sports bra market makes an estimated £5.5bn annually.


The impact of sports bras on women’s sport

It’s hard to imagine it now, but a lack of supportive undergarments were once a serious barrier to women athletes. The Amazons of ancient Greece would cut off their right breasts so they wouldn’t get in the way of their archery. Women competing at Wimbledon in 1887 reported bloody corsets, having been repeatedly stabbed in the ribs as they played. Most horrifying of all, French sportswoman Violette Morris had a double mastectomy in the 1920s so she could fit behind the wheel and compete in motor racing.

We should never underestimate the impact the sports bra on women’s sport because it’s been nothing short of revolutionary. "If I forgot my sports bra, forget it, I just wouldn't compete," says Goldie Sayers, 11-time British javelin champion. "That's how integral it is to my performance."

And in 2019, for the first time ever, the Women’s World Cup teams made a sports bra part of their official kit.


Pour Moi sports bras: designed by women, for women

The history of the sports bra sees women innovators designing for women athletes. And Pour Moi’s own sports bra continues this story of women supporting women.

Our sports bras were designed by Pour Moi’s head of design Julie Kendall (with the help of junior designer Caitlin Arthur), and were extensively tested by female athletes who let us adjust the prototypes as a result of their feedback.

We gave our sports bras to marathon runners and beach volleyball players who play at Yellowave Beach Sports Venue in Brighton, and they really put our designs through their paces! We made sure we tested on women who had larger bust sizes so that we knew for sure our sports bras would offer unparalleled levels of support. After all the trials were complete, we took all our women athletes’ feedback into consideration, and even added extra features based on their wearer trials.

The result? A range of sports bras that we know look great, feel soft and supportive and, above all, minimise the bouncing for every woman at every size.

Read our sports bra wearer trials blog post.


Why should you wear a sports bra?

The average bra size in the UK is now a 36DD and, although breast density differs between women, that’s thought to weigh about 550g per breast. So the average woman is carrying around over a kilo of weight on the front of her chest that moves independently to the rest of her body.

Breasts may sit on top of the pectoral muscle, but they’re made of fat and glands and contain no muscle themselves. They’re supported only by skin and some delicate, paper-thin connective fibres known as Cooper’s ligaments. These weave throughout the breast tissue to attach it to the chest wall. But while the skin and supportive structures are able to resist a certain amount of strain, overstretch them repeatedly and they can’t return to their original shape.

Thought you’d get away with it because your breasts are small? No such luck. Even 34A cup sizes have been shown to bounce up to around 4cm which can also lead to breast sag. But the good news is that, whether your breasts are large or small, the right shock absorber sports bra can reduce bounce by up to 80 per cent - that's twice as much as a normal bra.


How wearing the right sports bra can improve your performance

Got your eye on a new PB? Forget new trainers, because the answer may lie in your sports bra. From your breathing to your running stride, research from the University of Portsmouth shows that the way you run all depends on the bra you’re wearing.

When breasts aren’t supported, women have to work harder to run because they increase their upper body muscle activity. With this comes a change in breathing patterns, with women shown to take smaller, shallower breaths if their bra isn’t supportive enough.

Their running gait was also found to change, with 4cm lost in stride length! So if you’re in the market for new trainers and are doing a running gait test, make sure you’re wearing a good sports bra or you could end up with the wrong shoes.


How to choose the best sports bra

Sick of rib-crushing bands, chafing underarms or sore straps? According to Pour Moi garment technologist Lois Siciliano, “To be really effective, your sports bra needs to fit like a glove. All the sports bras at Pour Moi come in cup sizes rather than dress sizes so it’s easy to find your perfect fit. Just go for your normal bra size and try the following tips to make sure it’s the best sports bra for you.”


1. Consider the kind of exercise you’ll be doing

“Are you looking for a sports bra for running? Then high impact styles (such as our Energy Underwired Lightly Padded Convertible Sports Bra or the Energy Non Wired Full Cup Sports Bra will be perfect.

But don’t reject a medium impact sports bras like the Energy Underwired Lightly Padded Sports Bra, particularly if you’re doing an activity that involves a lot of different movements, such as dance, yoga or pilates. That’s because moderate impact sports bras usually have features particularly suited to keep you contained and comfortable when you’re moving, bending, stretching or twisting.”


2. Don’t be put off by padding

“Worried that padding may look you look bigger up top? Lightly padded styles such as the Energy Underwired Lightly Padded Sports Bra and the Energy Underwired Lightly Padded Convertible Sports Bra are excellent for adding more shape and support, and they can eliminate things like nipple show-through and chafing.”


3. Choose underwire for more shape and support

“If your breasts are large, you may hate that undefined, squashed together look you get from typical compression crop top style sports bras that flatten your breasts against the chest wall. Choosing a sports bra with underwire such as Energy Underwired Lightly Padded Sports Bra or the Energy Underwired Lightly Padded Convertible Sports Bra can avoid this, as it keeps breasts both separated and fully supported, with no more ‘uni-boob’ effect.”


4. Put the sports bra through its paces

“Try on the sports bra, then do the bounce test as if you were running. If there’s too much movement, you may need to go down a cup size. There should be no chafing at the underarms, shoulder straps or seams. Raise your arms over your head and check that the band doesn’t ride up - if it does, you may need to go down a band size.”


5. What areas to look out for

“The underband is the most important part as this is where all the support comes from. It should sit horizontally the whole way round (and not ride up at the back) and feel more snug than your normal bra, but not so tight that it digs in.

The underwire should follow the natural crease of the breast, and not sit on the breast tissue, while the breasts should be enclosed within the cups with no bulging over the top or gaping at the sides.”


How to care for your sports bra

To make sure your sports bra lasts even longer, wash it in cold water, avoid fabric softener and do not tumble dry, as the heat may degrade the fabric.


How to wear a sports bra

It used to be that our grey, grubby sports bras never saw the light of day. But with colours, patterns and styles, this is one item of underwear that can definitely be worn as outerwear.

Even if you don’t dare to bare yours fully, a loose vest worn over a sports bra will make sure those cool racer backs and vibrant design details can still be seen.

Whether you’re a yoga bunny or a weekend warrior, our range of sports bras can help you workout in style, feeling fully supported. They’re winning five-star reviews from women all over the UK and beyond thanks to their affordability, comfort and fit. Isn’t it time you tried one for yourself?

Pour Moi Insights