Range of motionROM

Range of motion (ROM) is the extent of movement around a joint, or the distance a load travels during an exercise — from a full deep squat to a shallow partial, for example.

It matters because training through a full range, especially the lengthened (stretched) portion of a movement, tends to produce more muscle growth than short partial reps, while also maintaining mobility. There are specific cases for partials, but full ROM is the sensible default.

In practice, using a controlled full range you can actually stabilise — rather than bouncing through a range you can't own — is a reliable way to get more from each rep.