Second-hand gym clothes and activewear: what to check and how to wash it

When you buy second-hand activewear, check that the fabric still stretches and springs back, that leggings are not see-through when stretched, and that there is no heavy pilling on the inner thighs or underarms. Look at the seams, waistbands and any printed logos for cracking, and ask whether the piece has any lasting smell, since synthetic fabrics can hold on to it. Go by measurements in cm as well as the size, and wash everything before you wear it.

Gym clothes and activewear are often bought with good intentions and worn only a few times, so many second-hand pieces still have plenty of life in them. Here is how to pick good pieces and keep them that way.

What activewear is made of

Most activewear is made from synthetic fibres, usually polyester or nylon, with elastane for stretch. These fabrics are strong, quick-drying and move moisture away from the skin. Some pieces use merino wool or cotton blends, which feel softer but behave differently.

Our fabric guide to cotton, linen, wool and polyester explains how each fibre behaves.

What to check on second-hand activewear

Stretch and recovery

Stretch a small section gently and let go. It should spring straight back. If it stays baggy or rippled, the elastane may have weakened, and the piece will sag during exercise. Pay particular attention to:

waistbands on leggings and shorts
the knees and seat of leggings
cuffs and hems on tops

Sheerness

Leggings that are fine when relaxed can turn see-through when stretched. Ask the seller to stretch the fabric over a hand and photograph it against the light. This matters most for lighter colours.

Pilling

Bobbles form where fabric rubs, on the inner thighs of leggings, under the arms of tops, and where a bag strap sits. A little is normal and can be removed. Heavy pilling is hard to fix on smooth, tight-fitting fabrics. Our guide to removing bobbles explains how, but go gently on thin activewear.

Seams and stitching

Activewear seams are often flat or bonded, so they do not rub. Check that they are not splitting or peeling, especially at the crotch of leggings and the underarms.

Prints and logos

Printed logos and reflective details can crack or peel with washing and heat. Check them closely in the photos.

Pockets and zips

Check that zipped pockets work and that phone pockets on leggings are intact.

Smells

Synthetic fabrics can hold on to sweat smells, even after washing. Ask the seller whether there is any lasting smell. Our guide to getting smells out of second-hand clothes has gentle ways to freshen activewear, such as a soak in diluted white vinegar before washing.

Sports bras and swimwear

For sports bras, check the size label, the band elastic and any adjusters, hooks or clasps, and look for padding that has shifted or broken down. Labels often describe the level of support for different activities, which helps you choose. Swimwear is listed separately on Rewear, but the same stretch and sheerness checks apply.

Getting the fit right

Activewear sizes vary between makers, and stretch makes the fit more forgiving in some places and less in others.

Ask for the waist, hip and inside leg in cm, laid flat and unstretched, for leggings.
Compare them with a pair you own and like the fit of. Our guide to measuring clothes for buying online shows how.
Ask for the chest and length for tops.

On Rewear, tap Message the seller on the listing if the measurements are missing. They are optional, so not every piece has them.

Washing activewear so it lasts

Wash it after every wear, rather than leaving it damp in a bag.
Turn it inside out to protect the outer surface and help clean the side that touches your skin.
Wash cool, often at 30°C, using the care label as your guide.
Skip fabric softener. It can coat technical fabrics and stop them wicking moisture properly.
Close zips and hook-and-loop tabs, so they do not snag other pieces.
Use a mesh laundry bag for leggings and sports bras.
Dry it on a rack or line, out of direct sun. Avoid the tumble dryer unless the label allows it, because heat weakens elastane.

Selling activewear

If you have gym clothes you no longer wear, sell them while the fabric is still in good shape.

Wash them and check for smells.
Photograph them in daylight, laid flat, front and back, with a close-up of the fabric.
Show the stretch with a photo of the fabric over your hand against the light.
Give the size and measurements in cm.
Mention any pilling or wear honestly.

The new year and spring are when many people start new routines, so they can be good moments to list.

The short version

Check stretch and recovery, sheerness, pilling, seams and smells. Go by measurements, wash everything cool and inside out with no fabric softener, and dry it away from heat. Sell what you no longer use while it is still in good shape.

Find your next piece

Second-hand clothing from sellers across the UK, with measurements in cm where sellers add them and buyer protection at checkout.

See what’s for sale Sell on Rewear