Plyometric training stimulates a specific pattern of muscle fibre activation that enables the muscle to generate a powerful contraction in a short amount of time
A plyometric contraction initially involves a rapid muscle lengthening movement (eccentric phase), followed by a short resting phase (amortisation phase) and then an explosive muscle shortening movement (concentric phase). This process is known as the strength-shortening cycle (SSC), a process which has the potential to generate more power than a normal muscle contraction because muscles and tendons are able to store potential energy from the stretch for a short period of time, much like a spring, and then release it forcefully. In this way the vertical jump is a beneficial exercise to improve strength, speed, power, explosiveness, and agility.
Caution: This highly advanced and technical exercise is only suitable for experienced gym-goers and athletes. A suitable progression would include:
- Bodyweight squats
- Jump squats
- Box jumps
- Step offs
Tip: Proper landing technique is essential for safe and effective execution. There should be no valgus (outward twist) or varus (inward twist) knee collapse on landing. Your ankles and feet also need to remain stable during the loading and de-loading phases.
Note: Taking too much time to transition from absorbing the impact of the landing into the jump (the amortisation phase) reduces the power-generating benefit of the movement.
- Starting: Stand on box or stacked aerobics step, close to the front edge.
- Execution: Step off the box and land on both feet. Immediately jump up off the ground, reaching up with both hands to jump as high as possible. Land softly and step back up onto the box to repeat the movement. Aim to perform 2-4 sets of up to 10 reps, with 2:00 of active recovery between sets.
- Primary: Hip extensors (gluteus maximus, hamstrings, adductor magnus) and knee extensors (quads)
- Synergists and stabilisers: Ankle stabilisers (calves and tibialis posterior), shoulder adductors (deltoids, supraspinatus, pectoralis major) and flexors (trapezius, levator scapulae, serratus anterior), and core stabilisers including erector spinae.
Contra-indicators: Do not perform this exercise if you are suffering from any tendonitis, tendinosis, or hip, knee and/or ankle injuries.