Developing Power in Everyday Athletes with Plyometrics.
Power is the ability to quickly produce large amounts of force. Are there any athletes that would not want to improve their ability to generate power? What about clients seeking to improve general fitness? Power is essential for both groups. By incorporating plyometric exercises into training programs, the speed and force of movement can be harnessed for improved performance and daily activities.
Plyometric exercises have three distinct phases, an eccentric phase, an amortization phase, and a concentric phase that releases the explosive force. These three phases make up a stretch-shortening cycle. During the eccentric phase, the muscle is prestretched, storing potential energy in the elastic components of the muscle (1-3). The eccentric phase has also been referred to as deceleration, loading, yielding, or the cocking phase (1-2). When basketball players bend their knees and lower their arms before a rebound shot or when a baseball player pulls his arm back before a throw to first base are both examples of the eccentric phase.
The amortization phase is a time of dynamic stabilization during which the muscle transitions from loading the energy to releasing it. If this phase lasts too long, the potential elastic energy can be lost. The shorter the amortization phase, the more powerful the results.
Unloading the energy occurs next in the concentric phase, adding to the tension generated in a concentric muscle contraction. This is where the athlete releases the stored and redirected energy, jumping for the basket or slinging the ball to first base.
Before incorporating plyometric exercises, athletes and clients alike must have the ability to balance efficiently, and possess adequate core strength, joint stability and range of motion. Plyometric drills may not be suitable for those with chronic or limiting conditions (1,2). Following the NASM Optimum Performance Training ™ (OPT™) model, plyometric exercises progress from stabilization (e.g., squat jump with a 3-5 second stabilization hold on landing), to strength (e.g., tuck jump), then to power (integrated, functional movements performed at a quick tempo such as ice skaters) (1,2). Plyometric exercises aren’t limited to the lower body. There are upper-body activities, including plyometric push-ups, wall throws, overhead throws, or combination moves such as a jump squat with a chest pass.
Of the many benefits of plyometric training, some of the more recognized are increased vertical jump height, long jump, strength, improved running speed, and injury prevention (1,4). It’s probably easier to see how plyometric training can be used to improve athletic performance, but perhaps more difficult to see why plyometric exercises would benefit the non-athlete. Plyometrics is interchangeably termed reactive training. From this perspective, it is essentially about how the body interacts with ground surfaces. Being able to quickly respond to an unexpected change in surface when stepping off a curb, or to rapidly change direction when walking a dog on leash are possible examples clients may encounter (1,5). Begin with activities that focus on plyometric stabilization exercises, even using regressions such as step-up/step-down or step-up/step-down to the front on a low box or bench.
Recall that plyometric exercises are based on three phases, an eccentric phase that stretches the muscle, the amortization phase focusing on dynamic stabilization, and the concentric phase that concentrically contracts the muscle. Many exercises are secretly plyometric exercises if they incorporate explosive moves. Progress plyometric exercises safely by going from easy to hard, simple to complex, known to unknown, stable to unstable, body weight to loaded, or activity specific (1,2).
- Clark, MA, Lucett, SC, Sutton, BG. NASM Essentials of Personal Fitness Training 4th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2012.
- Clark, MA, Lucett, SC. NASM Essentials of Sports Performance Training. Baltimore, MD: Lippincott Williams & Wilkins; 2010.
- Chu, DA. Jumping Into Plyometrics 2nd ed. Champaign, IL: Human Kinetics; 1998.
- Fleck, SJ, Kraemer, WJ. Desgining Resistance Training Programs 2nd ed. Champaign, IL: Human Kinetics; 1997.
- Rose, DJ. Fall Proof! A Comprehensive Balance and Mobility Training Program. Champaign, IL: Human Kinetics; 2003.