BYT

Squat · Machine · Learn first

Leg press

Sit in a 45° sled with your back and hips flat on the pad. Feet about shoulder-width in the middle of the platform, toes slightly out.

Leg press
  1. 1Lower until the knees pass about 90°, and stop before the hips peel off the pad.
  2. 2Knees track over the toes. Heels stay down.
  3. 3Press through the whole foot until the knees are almost straight. Don't lock them.

Easy to miss: Going so deep the low back rounds off the pad, or snapping the knees straight.

Muscles

Copper on the figure is a prime mover. The softer tone helps.