It is simply a small portion of the over all picture. In fact, the emphasis here is athletes must have a base of these three components before plyometric training can even be utilized. If the athlete has an inadequate base of flexibility, aerobic fitness, and over all strength, then poor results and injury are inevitable. Anyone involved in sport needs to utilize a consistent stretching regimen. Stretching should take place before and after each training session and should include exercises for legs, hips, butt, back, and upper-body.
Plyometric training is an anaerobic training program.
Therefore, in order to maximize athletic performance a solid aerobic base should be in place before beginning a plyo training program. For more aerobic fitness exercises and guidelines, see my articles on Basic Soccer Fitness. Pumping iron is an ideal partner to plyo training as it helps increase base strength and prepares the muscle for the demanding movements of plyometrics. It will not only increase performance, but will build a base of strength which will prevent injury. With this in mind, the more intense the plyo work outs, the more intensive and essential strength training becomes.