According to About.com’s Sports Medicine Section
Plyometric exercises are specialized, high intensity training techniques used to develop athletic power.Plyometric training involves high-intensity, explosive muscular contractions that invoke the stretch reflex (stretching the muscle before it contracts so that it contracts with greater force). The most common plyometric exercises include hops, jumps and bounding movements.
Simply put, plyometrics are exercises which utilize the body’s own weight and movement to develop athletic strength and speed.
As wisegeek explains
Plyometric exercises are beneficial because they require an athlete to perform very explosive motions. By recruiting the muscle tissue quickly, the exercises increase the efficiency of the neuromuscular system. Rather than simply increasing the amount of muscle tissue on an athlete’s body, then, plyometric training allows the athlete to make more efficient use of the muscle tissue that he or she already has. This makes the muscles stronger without necessarily increasing their overall mass, which allows them to move faster.
Controversies Surrounding Plyometrics
There is little controversy as to the safety and effectiveness of plyometrics for adults and in advanced training. However, the use of plyometrics with children and adolescents has been controversial.
This is largely as a result of outdated research, a lack of understanding by coaches about the impacts it has on an athlete, and the prescription of too much training volume.
According to the American College of Sports Medicine,
plyometric training is a safe, beneficial and fun activity for children and adolescents provided that the program is properly designed and supervised.
Plyometric training may not only make children and adolescents faster and more powerful; this type of training may offer observable health benefit to young populations. The contention that plyometrics are inappropriate for boys and girls is not consistent with the needs of children and teenagers or their physical abilities.
In fact, plyometric training for youth is supported and recommend by nearly all major athletic training and medical organizations today, including The National Strength and Conditioning Association, US Soccer, and The American Council on Exercise to name a few.
The fact is, even jumping rope is a form of plyometric exercise.
Whether youth or adult, it is important to take adequate safety measures for plyometric training – or any other training.
Consider these guidelines to prevent plyometric related injury:
- When doing “jump” exercises, use good landing technique – When landing, the load should be supported by the leg muscles and not the knee ligaments. Knees should be flexed and the legs should remain parallel – knees should knock point either in nor away from each other.
- Start small – Unlike many other exercises, with plyometrics, more is not always better. As a guideline, plyometric training should occur no more than every 48-72 hours. Also, lower-impact plyometric exercises may allow for more repetitions, but higher-impact exercises should be limited.
- Start easy – Progress in your routine. Begin with easier exercises, lower intensity, and fewer reps (as per the NCSA: college-level athletes should begin with 100-150 foot contacts per session; lower-level athletes should adjust that number down). Gradually progress as your neuro, muscular, and skeletal systems progress as well.
- Have an adequate “base” of strength before undertaking plyometrics – This should not be a problem for most young athletes, however, those of a “fragile state” (bone, muscle, tendon problems, etc) as well as athletes that are severely overweight should minimize plyometric training.
- Have an appropriate landing surface – Avoid surfaces like concrete and asphalt. Instead use cushioned surfaces such as grass. The landing area should also be free of clutter and other hazards (such as uneven surfaces and cracks) which can lead to twists, sprains, falls, etc
- Avoid plyometrics when injured – This is particularly important during knee and ankle injuries which are more frequent in soccer.
- Use appropriate height for jump exercises – Higher falling and landing heights are a greater risk to cause injury.
- Young Children (under 10) – Ground exercises only
- Beginner – a few inches; about 1/2 of shin height
- Intermediate – top of shin (just below the knee)
- Advanced – by ability