Lean from the ankles, not the waist.
Many runners either run bolt upright or fold at the waist. A waist fold collapses the hips, kills hip extension behind you, and forces your quads to do all the work. Leaning back is worse — it puts the brakes on every step. The fix is a slight whole-body lean sourced at the ankles, with a tall crown and ribs down.
What good looks like
Slight ankle-sourced lean, tall through the crown, ribs down — never a waist fold or back-lean.
Fix it: 2 cues + 1 drill
1 · Cue
Lean from ankles, not waist
2 · Cue
Tall through crown, ribs down
3 · Drill
5x20m fall-forward wall leans
Fix the next zone
Stop Overstriding
Increase Running Cadence
Arm Swing
Head Position for Runners
Relaxed Shoulders While Running
Hip Drop When Running