The fitness-fatigue theory is believed to better represent how an athlete's performance improves after a training session. And in 2003, Loren Chiu and Jacque Barnes wrote a nice overview of the fitness-fatigue model and compared it with the traditional super compensation theory model. Fitness-fatigue theory proposes that we need to view fitness and fatigue effects as separate entities. The fitness effect improves the athlete's physiological capacity whereas the fatigue effects decrease it. The athlete's performance depends on the Difference between the Fitness and the Fatigue effects. This chart here illustrates the fitness-fatigue effect due to a Training session. It's a different look from the super compensation theory graph. After a training session, the fitness gain is moderate, but it is long lasting. The Fatigue effect on the other hand is greater than the fitness effect. As you can see by the depth of the graph here, but its duration is much shorter. If you consider both the fitness effect and the fatigue effect, the change in fitness would look something like the blue line. Now according to Zatsiorsky, the duration of the fitness effects after a training session last three times longer than the fatigue effects to. And this means that if the negative effects, or fatigue, lasts for 24 hours, the positive fitness effects from this training session will last for 72 hours. The goal of the coach using the fitness fatigue model is to time the next training session when the fatigue effects of the preceding training session are largely dissipated. But before the fitness effects have completely disappeared. Fatigue is not an issue for coaches guided by super compensation theory because this theory predicts that fatigue has completely dissipated at the height of super compensation. The two models suggest a different tapering philosophy, and we'll talk more about tapering in the next lesson. So when tapering or peaking an athlete for competition, the Supercompensation theory suggests decreasing the frequency of training while keeping the same training loads. The athlete attempts to compete at the peak of supercompensation. Recovery days before competition or time so supercompensation peaks on the competition day. Fatigue, remember, is not considered because it is thought to be already dissipated at the peak of supercompensation. Now a coach using the Fitness-fatigue theory believes that the goal is to avoid accumulating fatigue during the final phase of preparation for competition while simultaneously stimulating high fitness effects. The Fitness-fatigue theory coach will keep the frequency of training the same but reduce the training load. Now Zatziorsky graphically represents the fitness and the fatigue effects in a slightly different way, and I really do prefer his way of looking at it. The fitness effect is highest immediately after the training session with the effects gradually declining back to baseline. The fatigue effects are also highest after the training session by the depth of the chart, and they gradually decline back to baseline. So it's becoming increasingly less negative. Now as the fatigue effect declines the athlete experiences a gradual increase in level of performance. And the athletes peak performance does not reach baseline until almost only fatigue effects have disappeared. An athlete is never able to use most of their fitness effects that they, that was stimulated by the training session. Due to the fact that there is always a lingering fatigue effect. Now once all the fatigue effects have dissipated the remaining fitness effects contribute to the athlete's level of preparedness or fitness for the competition. Now as you see here, only a small amount of fitness effect remains after removal of all the fatigue effects.
