Strap in low, drive the knee like a sprint.
Stay tall and stable on the standing leg, drive the knee high without leaning back.
Cuffed at the ankle and facing away from the stack, you are loading the exact sprint gesture of punching a knee up toward your chest, with the quads' hip crossing fibres doing the driving. Meanwhile the standing side's glute works overtime keeping you tall and stable on one foot. Each leg trains alone, which is precisely how legs work when you run.
Anyone chasing sprint speed, acceleration or a stronger stride, plus lifters who want single leg stability work that is not another lunge. It is a power and control drill more than a mass builder.
Drive up with intent, control the lowering. The explosive knee punch is the point of the drill, but letting the cable yank your leg back down wastes half of every rep.
You are leaning away to help the knee up. Stay stacked and tall on the standing leg, drop the weight if needed, and think about the knee travelling up your midline rather than your torso reclining to meet it.
