All fours on the box: Lift the working leg to a bent position like a frog with the rope under the knee, creating a slight hip opener. Exhale to extend the leg away.
1B.
Down or up.
Long Box.
Exhale to push away, inhale back.
Develop strength of the core, internal and external obliques, scapular stabilisers, gluteals, and hamstrings.
Progression: 1B, 1Y.
Regression: 1B or 1Y.
Modification: Carriage leg press or side-lying leg press.