Depth Jump (Drop Jump)

In a depth jump (drop jump) the athlete steps off a box (does not jump off), drops to the ground, and on landing immediately rebounds into a maximal vertical (or sometimes horizontal) jump with the shortest possible ground-contact time. The pre-landing drop loads the muscle-tendon units rapidly (eccentric), and the instantaneous rebound exploits the stretch-shortening-cycle — making this the prototypical fast-SSC, reactive drill.

Technique: step (don't jump) off the box, land on the balls/whole foot with stiff but absorbing ankles, minimize ground-contact time ("off the ground fast"), and explode upward immediately with an arm swing. Land the rebound softly under control.

Box height is critical and is the main dosing variable: typically ~30-60 cm (≈12-24 in), individualized so that contact time stays short and rebound height is maximized — if landing is heavy/slow or rebound drops, the box is too tall. optimal drop heights vary by athlete and goal.

This is a high-intensity, high-impact drill: it requires the strength and technique prerequisites (commonly a back squat ~1.5× body weight), a good surface, and conservative volume/recovery. The drop-jump is also the standard test for the Reactive Strength Index (jump height ÷ contact time).

• Step off a box, land, and rebound immediately into a maximal jump (fast SSC / reactive).
• Highest-intensity plyometric; minimize ground-contact time.
• Typical box height ~30-60 cm (12-24 in), individualized to keep contacts short.
• Requires strength base (~1.5× BW squat), good surface, low volume, full recovery.
• Standard drill for the Reactive Strength Index.

• reactive-strength — the quality this drill builds and tests.
• stretch-shortening-cycle — the fast SSC is maximally loaded here.
• box-jump — different intent (jump up vs step off and rebound).
• plyometric-prerequisites — strength/technique gates before depth jumps.
• landing-mechanics — critical given the high impact.