Ken Grace
Chabot College
Principles of Plyometric Training
Plyometric training can act as the bridge
between strength, power, speed and skill. Plyometric training utilizes the
stretch reflex mechanism in the muscle to improve the reaction time of the nervous
system in that muscle. The goal of plyometric training is to develop the power
and speed that is specific to a sport.
Plyometrics work by quickly stretching the
muscle (eccentric) followed by a very quick muscle contraction (concentric).
The quick eccentric phase activates and fires the muscle spindle, located in
the muscle fiber, and a tremendous amount of force is generated through elastic
energy that is stored in the tendons and muscle.
Each time a specific and correct plyometric
action is practiced the nerve synapse and the muscle it innervates, becomes
better at transmitting the same signal in the future. These synapses over time
can increase the receptor sites for greater excitation of the muscle. Simply
put the body learns to create to a faster and greater muscle contraction.
The key to plyometric exercise is to keep
the amortization phase (the landing and pre-stretch phase) as short as
possible. This phase is significant. If the loading phase is too long the Golgi
Tendon Organ will take over and cancel out the function of the Muscle Spindle.
The shorter the amortization phase, the greater the muscle spindle action and
elastic response from the muscle and the nervous system. The amortization phase
should be between .003 to .005 seconds. The athlete must always react as if the
ground is hot like a frying pan. As soon as ground contact time increases, or
fatigue is noticed, it is time to stop the exercise.
Guidelines to
Follow:
1. Plyometric
Exercises should be performed at 100% effort. Plyometric training is an Alactic
Energy System exercise.
2. Each set should
last no longer then 6 to 8 seconds.
3. Full recovery
should occur between sets.
4. Plyometric
exercises should be progressive in intensity. Start with easy exercises and
develop in intensity and complexity.
5. The skill and
speed of performing a plyometric exercise is of great importance. Stop before
fatigue breaks down technique.
6. Before you start
a plyometric program follow with a progression of exercises that will lower
some of the inherent risk of injury using plyometric training:
A. Start with standing long jump landing on two feet and
sticking the landing.|
B. Jump to a Bench knee height and stick the landing. Use the arms to help with the jump. Swing and block the arms at
take off.
C. Single leg jumps in place.
D. Single leg squats with just body weight off of a bench or box.
E. Short Jumps ? 5 to 6 double leg jumps.
Short jumps upstairs.
F. Alternate Leg Bounding ? 3 to 5
jumps on the grass.
G. Single leg hops upstairs.
|
Intensity Rating & Type of Exercise |
Intensity of Exercise |
Number of Reps and Sets |
Rest Interval Between Sets |
Recovery between Plyometric Workouts |
|
5 - Rope Skipping, Hops on Spot, Light Implements, Throws |
Low |
10 to 30 reps |
2 to 3 minutes |
very rapid |
|
4 - Simple Bounding, Medicine Ball, Low Short Hops, Two Leg jumps, Steps, stair Jumps, Tuck Jumps |
Moderate |
10 to 25 reps |
3 to 5 minutes |
One day required |
|
3- Two Leg Jumps from height, Upper Body, Medicine Ball for Distance, Shot Throws, Low Drop Reaction and Rebound, 2 leg and 1 leg bounding |
Sub-Maximal |
3 to 25 reps |
3 to 5 minutes |
1 to 2 days |
|
2 - Medicine Ball Shocks, Drop Jumps, bounds for distance, hops or similar long jumps |
Very High |
5 to 15 reps |
5 to 7 minutes |
2 days |
|
1 - High Reactive Jumps, Shock hits, Heavy Implements, In Depth Jumps |
Maximal |
3 to 5 reps |
8 to 10 minutes |
3 days required |
Progress and development through the five
degrees of intensity is a long-term proposition. The incorporation of low
impact exercises into the training program for young athletes, for 2 to 4
years, represents the time needed for the progressive adaptation of the
ligaments, tendons and bones of the body (Bompa).