Sports bras: size and support for every sport

How much support a sports bra needs to give depends on how much your upper body moves up and down in your sport. For yoga and calm strength training, low to medium support is usually enough; for classes and cycling, medium; for running, jumping and ball sports, high support. You work out the right size from your underbust and bust measurements, but you always have to check it when trying the bra on, because sizes differ from brand to brand.

Which level of support suits which sport?

Retailers usually divide sports bras into three levels: low, medium and high impact. This is a common retail classification, not a uniform technical or medical scale: each brand decides for itself what it calls medium or high support. A common way of matching sports to levels, as used for example in the guide by Outdoor-Renner (a German outdoor retailer, in German):

• Low support (low impact): yoga, Pilates, stretching, leisurely cycling, hiking
• Medium support (medium impact): Nordic walking, spinning, climbing, strength training, many gym classes
• High support (high impact): running, aerobics, tennis, handball, volleyball and other ball sports

The classification is a guide, not a standard. Whether a model suits you also depends on cup size, cut and how it feels. With a larger bust, high support can feel better even for a medium-impact sport. What counts is how it feels when you move.

How do I measure my sports bra size?

With a tape measure, ideally over an unpadded bra. Stiftung Warentest (Germany's consumer testing foundation, in German) describes the method like this: measure your underbust directly under the bust, after breathing out. Then measure your bust at its fullest point. The difference gives the cup size in the EU sizing system used in Germany: with a bust of 95 cm and an underbust of 80 cm, the difference is 15 cm, which there corresponds to cup B, so size 80B. British and American sizes are calculated differently: they give the band in inches (80B is roughly a 36B), and above D the cup letters no longer match.

Many sports bras are not sold in cup sizes but in S, M and L. Then the brand's size chart helps, which matches underbust and bust measurements to the letter sizes. Some brands, such as Brooks, use their own sizing. If you are between two sizes, try both.

How can I tell that a sports bra fits properly?

Stiftung Warentest lists a few simple checks you can tick off every time you try one on:

• The underband sits close to the body, but does not dig in or ride up.
• On bras with a fastening: close it on the first or middle row of hooks, so you can tighten it later when the band gives.
• The straps do not dig in. Two fingers should fit under the strap at the collarbone.
• The cup encloses the whole breast, with nothing spilling out.
• If the calculated size does not fit, try a sister size, for example one band size smaller and one cup size larger.

It is also worth doing a quick movement test in the changing room: jump on the spot a few times, stretch your arms above your head, bend forward. If anything slips or a seam presses, the model does not fit.

Which sports bras give medium support for the gym?

For strength training, classes and cycling, medium support is the most common choice. The PUMA Mid Impact Fit Bra is made of UltraForm compression fabric with dryCELL moisture-wicking and is designed for medium-impact activities. The ONLY PLAY Daisy-2 Seam Bra is made of seamless fabric, has a racerback and non-removable pads. Under Armour explicitly names cycling, strength training and boxing for the HeatGear Authentics Mid sports bra. It is double-lined but not padded. The PUMA 4keeps Bra has 3 cm wide straps, a 3 cm wide brushed underband and removable pads.

Which sports bras give high support for running?

In running and jumping, the breasts move the most. Models with high support often use encapsulated cups that hold each breast separately, along with adjustable straps and a fastening. The Brooks Dare Racerback 2.0 and the Brooks Dare Scoopback 2.0 both have encapsulated cups, adjustable straps and a hook-and-eye fastening on the underband. The Brooks Drive Convertible has no encapsulated cups, can be worn as either a scoopback or a racerback and has a back fastening.

Crop-top style or sports bra: what is the difference?

A crop-top style bra (bustier) is a simple top with no fastening and usually no cups. It supports through elastic fabric and a firm underband. For yoga, gentle exercise and smaller busts, that is often enough, including under the shirt at the club. The Jako Bra Power is a sporty crop-top style bra with wide straps, an elastic underband and flatlock seams. The Erima Racing Bra has a racerback, an elastic underband and a high stretch content.

How can I tell a sports bra needs replacing?

By the underband. If you already close it on the tightest row of hooks and the band still rides up, or if a bra without a fastening offers hardly any resistance when you put it on, the material has given way. Stretched-out straps that can no longer be tightened and pads that shift after washing are signs too. There is no fixed number of months; it depends on how often you wear it and how you wash it. If you rotate two or three sports bras, you spread the wear over several pieces.

Checklist for buying

• Decide on your sport: low, medium or high support
• Measure underbust and bust, check the brand's size chart
• In the changing room: jump, stretch, bend forward
• Band snug but not digging in, two fingers under the strap
• Racerback or straight back: whichever feels better when you move
• Wash without fabric conditioner (fabric softener) so the fabric keeps wicking sweat

For questions about fit, it is best to try on several models in Bitburg or Prüm. How to wash sports bras and other gym clothes so they keep their stretch and function is covered in how to wash gym clothes. An overview of the fabrics in gym clothes is in gym clothes: which fabrics.