This is an excerpt from High-Powered Plyometrics 2nd Edition With HKPropel Online Video by James C. Radcliffe & Robert C. Farentinos.
Any program dedicated to enhancing athletic performance needs an ongoing method of evaluating its direction and the fitness and accomplishments of its participants. Jim Radcliffe knows this method better than most people. For nearly three decades he has served as the head strength and conditioning coach for the University of Oregon football team, refining his plyometric techniques to improve the strength, power, balance, speed, and endurance of one of America's most dynamic and fast-paced squads.
Before getting too far into planning the specifics of a plyometric program, Radcliffe says the prudent approach is to look honestly and carefully at issues that could affect safe participation in such intense training. In the updated second edition of his popular book High-Powered Plyometrics, he points to five factors that trainers must know about their athletes or that those planning their own programs should keep in mind and treat seriously.
- Age. Chronological age is an important consideration because the maturity of both the nervous and skeletal systems affects people's tolerance of plyometric training. For example, children who have not yet reached puberty should not participate in plyometrics because the continual growth of the skeletal system makes the extreme forces of some plyometric exercises inappropriate. Radcliffe and coauthor Bob Farentinos contend that 12- to 14-year-old participants can use plyometric training to prepare for future strength training but suggest using moderate jump training with children in this age range. They warn that adolescents do not appear to have any significant response to explosive strength training until after the onset of puberty; therefore, training programs should be prescribed cautiously. Conversely, as age increases, nervous system capability, muscle and joint pliability, and energy production decrease, which make plyometric training less suitable for older athletes.
- Physical capabilities and health limitations. As in all areas of exercise, good overall fitness is beneficial when training for explosive power. People should have good control of body weight and body composition, enough cardiorespiratory fitness to exercise continuously for at least several minutes, the strength to handle their own body weight in movements in all planes and directions, and the mobility to handle movement positions in several ranges of motion. Several physical areas should be assessed not only when planning training but also to determine limitations, such as flexibility, posture, balance, torso tilt, and joint alignment. “Limitations on explosive training may arise from back or spine problems,” Radcliffe warns. “Excessive trauma to these or any other areas that cause improper landing capabilities need to be addressed and planning adjusted.”
- Individual differences. Since athletes respond differently to training regimens, coaches need to be sensitive to their individual differences, while the athletes themselves must have some self-awareness. Differences between male and female athletes show up both in training and performance, and genetic makeup dictates, to a large extent, a person's ability to improve. While athletes and coaches need to be aware of limitations that can arise in training and development, and that these limitations may affect the rate of an athlete's progress, they should not influence the basic design of the training regimen.
- Experience. The training age a participant brings to plyometric training can actually be more important than chronological age. Some athletes who have had several years of experience as competitors, for instance, have never trained for competition. Some maturing athletes have been extremely skilled in their athletic endeavors and have enormous talent, yet they bring only an infantile level of training as a base. Radcliffe cautions that these athletes can be at high risk if they use poor technique and undertake exercise quantities for which their body structures are not yet ready.
- Strength training base. A strength base is advantageous in plyometric training, and a general strength training program should complement, not impede, the development of explosive power. However, establishing a strength base before plyometric training does not have to be a huge endeavor. Radcliffe and Farentinos recommend the often-prescribed Russian suggestion of being able to perform a maximal squat of one and a half to two times one's body weight before attempting depth jumps and similar shock training.
Radcliffe, who has coached world-class athletes like Ashton Eaton (an Olympic champion and world-record holder in the decathlon and heptathlon) and two-time Olympian Nick Symmonds says these elements must be examined before beginning serious plyometric training. Coaches should also understand safe procedures, whether the athletes are properly equipped (appropriate attire and props), and whether good exercise progressions are in place.