A supportive and comfortable sports bra is one of the most important pieces of kit in your running arsenal. We look at some of the best…

The humble running bra has come a long way since its 1979 beginning when it was simply two jockstraps sewn together and known as the ‘Jockbra’. Understated? Sure, but for women sprinting sans support, it was a performance-enhancing revelation. Fast forward 42 years and the running bra has become an impressive feat of engineering.

In a bid to reduce breast pain during physical activity, scientists have measured the way boobs bounce, and discovered that they move in a butterfly-shaped motion – researchers at the University of Portsmouth report that breast tissue moves 50 percent up and down, 25 percent forwards and backward, and 25 percent side-to-side. That’s a lot of movement to keep under control while you run.

And further data shows that insufficient support can do more than cause a bit of discomfort – it can reduce the activity of the pectoral muscle by 55 percent, which is something that may even contribute to muscle fatigue. It doesn’t matter what speed you run at either – pace doesn’t appear to increase or decrease movement – so here’s what we should all consider…

The design

When it comes to running bras, high-impact support is crucial –there really is no debate about this. ‘There is a greater degree of breast movement during running compared to other sports,’ explains Laura Kong Brown, product manager for Runderwear. ‘The average bra size in the UK is 34/36D and at this size, each breast will weigh 500g!’ A well-fitted and supportive sports bra is, therefore, key, and there are two main types of running bras that fit the bill: compression and encapsulation.

‘A running bra is specifically designed for high-impact activity, for which additional support is required,’ explains Kong Brown. ‘Compression bras work by pressing your breasts against your chest to reduce movement. Encapsulation bras compartmentalize each breast into separate cups, like normal bras but with extra support. This controls movement across all three planes of the body (up and down, in and out, and side to side).’

The design you choose will ultimately come down to your personal preference, but encapsulation bras tend to boast the most high-impact support because they are designed to separate and support each breast individually.

Measure up

Finding the right fit matters, but getting measured during the Covid era has proven difficult. ‘Despite stores being closed, it remains vital that women measure their bra size at least once a year,’ says Kong Brown, who recommends these home tricks to check you’ve bought the right fit. It’s easy to see how hard it can be to find the right running bra, so we’ve followed up with a handful of our favorite bras to help you decide.

The underband: A good-fitting underband should sit flat across your back in a straight line. You should be able to fit two fingers in between your body and the band. When you buy a new sports bra, you should always wear it on the loosest hook – the extra hooks are a design feature so that when the elasticity wears over time, you can tighten the band.

The straps: In a well-fitted sports bra there should only be one inch of giving, meaning you can fit two fingers under the strap at the shoulder area.

The cups: A bra that fits properly will encapsulate your breasts perfectly. This means your breasts should not be spilling out of the bra. The signs of a poorly-fitted cup include having room between the cup and the skin or wrinkling in the cup of the bra, both of which indicate that it is too big.

SHOCK ABSORBER ULTIMATE RUN BRA, £46

Shock Absorber’s award-winning Ultimate Run Bra has long been the go-to for women who do high-impact activities such as running, pleasing both smaller and larger chested fitness fans alike. Its special design features an Infinity-8 support system, which counteracts the figure-of-eight movement breasts go through as you run, and University of Portsmouth tests show it reduces bounce by as much as 78 percent. Indeed, it’s a winner in our books for its padded and adjustable straps alone! We tried the non-padded version (available up to a G cup) but a padded option is also available (£49; available up to an F cup) for those who prefer molded cups. shockabsorber.

Best on test

RUNDERWEAR EASY-ON BRA, £55

The Runderwear bra has become a firm favorite among those in the running community of late and it’s not hard to see why. Indeed, it’s been so sleekly designed that you’ll barely notice it’s there. Featuring molded cups and an encapsulated cut, it keeps boobs supported whatever size you are because it’s available up to a GG cup. It doesn’t nip around the insides of the shoulder blades either, thanks to its open back rather than racerback design. The padded shoulder straps are a thoughtful extra for both small or large sizes, as they prevent straps and the adjustable clips on straps from digging in as you drive your arms. What’s more, the soft fabric wicks sweat away like no other bra on test – you won’t be peeling off a drippy, sweaty number with this option! Runderwear.co.uk

FREYA ACTIVE DYNAMIC SPORTS BRA, £34

While molded cups can flatter, they’re not for everyone, and we appreciate that sometimes only a non-padded option will do. Enter Freya Active’s hugely supportive Dynamic Bra, which we really rate for running. It works by encapsulating the breasts and anchoring them in place with a wide and strong, but equally soft and comfortable, underband. The fit is perfect, with the neckline cutting just above the chest to keep everything steady. The four-hook fastening at the back means that this bra continues to fit after multiple wears and washes. Plus, we love the addition of a J-hook fastener for choosing a racerback or open back option. freyalingerie.

ASICS ACCELERATE BRA, £40

Global running brand Asics not only masterfully creates running shoes and clothing, but also boasts high-impact support bras. Unlike the others on the test, this bra uses compression technology to beat breast bounce, making it a good option for smaller sizes. In fact, you’ll be surprised how much support a bra that fits over the shoulders can offer. Style is key here, as the higher cut and mesh paneling around the front means that you won’t think twice about wearing it as a crop top on hotter days. You can adjust the straps for a tailored fit, but it doesn’t measure according to bra sizes (available in XS to XL) so it’s worth considering whether that’s important to you. asics

MAREE SOLIDARITY, £64

Hats off to Mari Thomas, Maaree’s founder, and experienced tester. Frustrated she’d never find a bra that could suppress the upward bounce, she designed one herself. Enter a reassuringly substantial bra with a trademarked Overband – a curved panel that runs over the top of the breasts – that’s anchored, via adjustable side straps, to the very wide and supportive underband. All this works to banish a huge amount of breast movement and keeps a flattering silhouette, too. The bra comes in sizes 30C to 38G, can be worn racerback or classic style,