Stretch fabric is destroyed by two things: heat and chemical coating. Both reach it in the wash, not in class. Four rules, ordered by how much each one matters.
1. Never use softener
This matters most, and it is exactly what most people do. Softener works by laying a thin, waxy film over the fibres — that is what makes a cotton towel soft. But elastane is stretchy because the fibres can snap back; coat them, and that recovery degrades.
A legging washed with softener for six months will go baggy even if the fabric is excellent. That is not the brand’s fault.
Instead: nothing. Activewear does not need softening.
2. Maximum 30 °C, inside out
Heat is elastane’s second enemy. Above 40 °C the fibre begins to elongate permanently, and that cannot be reversed.
Turning it inside out solves two things: the outer face does not rub against the drum (so it will not pill), and the sweat comes out from the inner side, where it actually is.
3. Never a tumble dryer
If you keep only one rule of the four, make it this one after the softener. A dryer is not merely warm — it is hot and mechanical at once, exactly the combination that destroys elastane.
A legging dries in three to four hours at room temperature, laid flat or hung. The dryer saves twenty minutes and costs six months.
4. Do not leave it balled up in a bag
After class the sweaty legging stays in a ball at the bottom of the bag until evening. Two things happen: damp creases set into the fabric, and bacterial odour settles in deeply enough to survive a wash.
Instead: spread it out, or at least put it in loosely. Once home, straight into the laundry basket — not the bag.
And what you do not need to do
You do not need a special sports detergent. Ordinary liquid detergent without softener is entirely fine. And “activewear refresher” sprays cause the same coating problem as softener.
A laundry bag, though, is worth having: it protects bra clasps and catches some of the microfibres shed in the wash.
