Plyometrics
Also known as: plyometric training, jump training
Plyometrics are explosive exercises — such as jumps, bounds, and throws — that use a rapid stretch of a muscle followed immediately by a forceful contraction to develop power. They exploit the stretch-shortening cycle.
Plyometrics are exercises built around a rapid eccentric (lengthening) muscle action followed immediately by a powerful concentric (shortening) action. Jumping off a box and instantly rebounding upward, bounding, depth jumps, and medicine ball throws are all plyometric movements. The goal is not just strength but power — producing maximal force in minimal time.
The mechanism is the stretch-shortening cycle (SSC). During the quick pre-stretch, elastic energy is stored in the muscle-tendon unit and the muscle spindles trigger the stretch reflex, which increases motor unit recruitment. If the transition (amortization phase) between the stretch and the contraction is short, that stored elastic energy and reflex activity add to the voluntary contraction, producing more force than a concentric action alone. A long pause dissipates the advantage as heat.
Because plyometrics impose high impact and neural demands, programming matters: intensity is graded from low-level drills like ankle hops to high-intensity depth jumps, volume is counted in foot contacts, and athletes need an adequate strength base and proper landing mechanics before progressing. Recovery between sessions (typically 48 to 72 hours) protects tendons and joints.
Plyometrics are heavily tested on the NSCA's CSCS exam, which covers SSC physiology, the three phases of a plyometric movement (eccentric, amortization, concentric), program design variables, and safety prerequisites. The NPTE-PTA also touches plyometric progressions in late-stage rehabilitation, where jump training bridges the return from injury to sport.
Key takeaways
- Plyometrics develop power through a rapid eccentric stretch followed immediately by an explosive concentric contraction.
- The stretch-shortening cycle combines stored elastic energy and the stretch reflex to boost force output.
- A short amortization phase is critical — pausing between the stretch and the jump wastes the stored energy.
- The CSCS exam tests plyometric physiology, phases, and program design; the NPTE-PTA covers plyometrics in return-to-sport rehab.