Wall sit timer

Forty five seconds is a fair working set. Thighs parallel to the floor, back flat against the wall, knees stacked over ankles rather than pushed forward past the toes.

The common failure is sliding higher as it starts to burn, which quietly turns a hard hold into an easy one. If you cannot keep the thighs parallel, the set is finished, whatever the clock says.

It is one of the few lower-body holds that needs no equipment and no space, which is why it turns up in every hotel-room routine ever written.

Or set any length you like: gotimer.app