Final answer:
A multi-planar exercise is one that involves movement in multiple directions or planes of motion. The lunge is considered a multi-planar exercise as it involves movement in both the sagittal and frontal planes.
Step-by-step explanation:
A multi-planar exercise is one that involves movement in multiple directions or planes of motion. Of the options given, the lunge is considered a multi-planar exercise.
When performing a lunge, you step forward or backward and lower your body, which involves movement in both the sagittal and frontal planes. This exercise targets multiple muscles and helps improve balance, stability, and coordination.