Most women wear the wrong sports bra. Not the wrong size — the wrong support level. A bralette that's perfect for a yoga class is the reason your run felt uncomfortable, and a maximum-support bra in a pilates session just feels restrictive.
Here's how to match the bra to the training.
Why support level matters
Breast tissue is held by skin and Cooper's ligaments — and neither of those regains elasticity once stretched. During running, breasts can move several centimetres in a figure-eight pattern. The right sports bra reduces that movement significantly. The wrong one doesn't.
This isn't only about comfort. Inadequate support during high-impact training is a genuine cause of discomfort that stops women training as hard as they want to.
Light support
Best for: yoga, pilates, stretching, walking, rest days, wearing under an oversized tee
Light support bras are usually pull-on styles with soft, wide bands and no underwire. The goal is gentle containment and comfort rather than restriction. They tend to be the most comfortable to wear for long periods, which is why they've become everyday pieces as much as training ones.
Our cropped sports bra and yoga tube top sit here.
Medium support
Best for: weight training, cycling, hiking, cross-training, elliptical
This is the most versatile category and where most people should start if they're buying one bra. Medium support gives real hold through lateral and vertical movement without the compression of a high-impact style.
Look for a firmer, wider underband — the band does most of the supporting work, not the straps. Styles with a halter neck, like our pleated halter bra, distribute load across the shoulders and upper back, which helps during lifting.
High support
Best for: running, HIIT, boxing, dance, court sports, any repeated impact
High-support bras use a combination of compression and encapsulation, thicker bands, and often adjustable straps or a back closure. They're structured, and they should feel snug — noticeably firmer than a bra you'd lounge in.
If you're a D cup or above, this is worth prioritising even for medium-impact training.
How to check the fit
Support comes from the band. If the band is too loose, the straps take the load and dig into your shoulders — that's the most common fit failure.
- The band should sit level all the way around, not ride up at the back. You should be able to fit two fingers underneath, and no more.
- The straps shouldn't leave deep marks. If they do, the band is too loose.
- The cups should contain everything with no spillage at the top or sides, and no gaping or wrinkling.
- Do the jump test. Jump up and down in the fitting room or at home. Minimal movement means it's doing its job.
When to replace it
Sports bras wear out faster than people expect. The elastane that provides the support degrades with every wash and every wear.
Replace yours when the band feels loose on the tightest hook, the fabric no longer springs back when stretched, or the straps have gone slack. For a bra worn a few times a week, that's usually 12 to 18 months.
Washing cold and never tumble drying will meaningfully extend that — see our activewear care guide.
Which should you buy?
If you're buying one bra, buy medium support — it covers the widest range of training. If you run, buy high support and don't compromise on it. If you mostly do yoga or pilates, light support will be more comfortable and you don't need more.
Shop the full women's range at WTD.