Work toward the splits and stretch deep into the groin.
Stay within a stretch you can breathe through. Forcing depth is how you tear something.
The half centre split is the sensible road toward a full straddle, widening your legs from a straddle position and holding at the edge of a strong but breathable stretch. The adductors take the long, sustained tension here, gradually granting more width as they learn the range is safe. It earns its place for anyone wanting deeper squat stances, freer lateral movement or an eventual full split, progress made in centimetres over weeks, not forced in one session.
Months of consistent work for most adults, sometimes longer, and that is fine, every centimetre of width you gain pays off along the way. Stretch several times a week and measure progress monthly, not daily.
Both are valid, the movement starts from a wide straddle either way. Seated is easier to control and relax into, standing adds load through the legs, start seated and add the standing version as your range grows.
Use the breathing test, if you cannot breathe slowly and let the muscles soften, you have gone past a productive stretch. Sharp, stabbing or joint-line pain means back off immediately, muscle-belly tension you can relax into is the target.
