Performance fabric is not delicate, but it is specific. Nearly every piece of running kit that goes permanently smelly or loses its stretch was damaged by how it was washed rather than how it was worn. The good news is that the rules are few and they are easy.
Cold water, always
Heat is what breaks elastane. A hot wash will cost you the recovery in your waistband and the shape of your cuffs faster than a hundred runs will. Thirty degrees is plenty — modern detergents are formulated to work cold, and sweat is not a stain that needs heat to shift.
Skip the fabric softener
This is the big one. Softener works by coating fibres, which is precisely the opposite of what a wicking fabric needs. It clogs the structure that moves moisture, and once that happens the garment stops performing and starts holding odour. The effect is cumulative and mostly irreversible, which is why a shirt that smells the moment you start sweating usually cannot be rescued.
Wash it sooner than you want to
Leaving damp kit in a bag overnight is how odour becomes permanent. Bacteria do their work in the warm, wet dark, and once they are established in the fabric no wash fully clears them. If you cannot wash it immediately, at least hang it to dry first.
Turn the tumble dryer off
Hang it, or lay it flat if it has any structure to lose. Dryer heat is the second-fastest way to wreck technical fabric after a hot wash. Most running kit is dry in a few hours on a hanger anyway, which is less time than you think.
Inside out, zips closed, like colours
Reflective trim and printed graphics last considerably longer when they are not abraded against everything else in the drum. Closed zips stop the teeth catching on mesh, and turning garments inside out puts the wear on the side nobody sees.
No bleach, and nothing scented
Bleach degrades synthetic fibre. Heavily scented detergents leave residue that behaves like softener. A plain liquid detergent, used sparingly, is all any of this needs — and use less than the bottle suggests, since excess detergent is itself a residue problem.
Care instructions specific to each piece are listed on every product page.