Activewear sizing and fit: how to get it right online
Activewear sizing fails for a predictable reason: people order their usual letter instead of checking centimetres. Five minutes with a tape measure fixes it.
Take three measurements
- Underbust and bust — for tops and bras.
- Waist at the narrowest point — for leggings and shorts.
- Hips at the widest point — the measurement that usually decides leggings size.
- Measure over thin clothing, tape flat, not pulled tight.
Read the chart, not the letter
Sizing differs between brands and even between fabrics inside one brand. Always compare your centimetres to the chart for the specific piece.
When you are between sizes
- Compression and heavy training: take the smaller size.
- Comfort, long wear, everyday use: take the larger size.
- Ribbed and seamless knits: usually the smaller size, they stretch a lot.
- Brushed or thicker fabrics: usually your true size, they stretch less.
What good fit feels like
The waistband stays put through a squat, the fabric does not go transparent under stretch, straps do not dig in, and there is no bunching behind the knee. If you keep adjusting a piece in the first ten minutes, it is the wrong size or the wrong cut for you.
Care keeps the fit
- Cold wash, gentle cycle, no fabric softener — it clogs the fibres.
- Air dry; heat is what kills elastane.
- Wash inside out to protect the surface of the knit.
Related reading
Questions on this topic
What should I wear to my first gym session?
High-rise leggings or shorts, a supportive top, a t-shirt you can layer over it and trainers with a stable sole. Comfort and coverage matter more than anything technical at the start.
How many training sets do I actually need?
Two or three. That covers a normal weekly rhythm with laundry in between, and it is enough to see which fit you reach for first.
How do I know leggings are squat-proof?
Squat deeply in front of a mirror and look at the seat under stretch. If skin tone shows through, the knit is too thin for your size or for lifting.