Three Factor Model of Adaptation

By Mladen Jovanovic

For www.EliteFTS.com

I got the idea to create the three factor model of adaptation (3F) after discussing a thread on central nervous system fatigue. Here is the basic premise:

preparedness = fitness + fatigue + facilitation

Fitness, fatigue, and facilitation are “immediate” and specific effects of a training stimulus. Fitness is the level of a particular trait/ability. It’s the most “inertial” factor. It slowly rises and slowly falls (compared to the other two). Fitness increases the spent current adaptation reserve (CAR) or some form of “adaptation energy,” which should be “refilled” from larger “buffers” during unloading phases. This is one of my premises for wave-like loading and unloading principles. Others include fatigue accumulation, trait synchronizations, rest, and general/specific ratios. Fitness increases are limited by the upper genetic limit and the genetic adaptation reserve (which can be spent prematurely by constant training and stress before even reaching the upper genetic limit).

Fatigue is (according to my understanding) an “expression” (or sensation like RPE or tiredness) of control mechanisms that limit performance to protect the body from damage or death. It can have various forms and properties such as the delayed phenomena in HI CNS fatigue. Like fitness, fatigue is also specific. It’s always a negative sign (contrary to fitness) and is related to fitness. As the athlete advances, he need more stress to produce only a small increase in fitness, but this increase causes a great amount of fatigue.

Facilitation is the shortest effect of a training load. It’s called post-tetanic potentiation (PTP), but it may be also due to arousal or stimulants. Higher facilitation can cause higher levels of fatigue afterward because of higher amounts of taxing on the system. It can have positive effects as well as negative effects on performance depending on the level of it. All three of these factors are conceptual and interconnected.

The speed of adaptation/improvement depends on the “dose-response,” or the amount of work/load needed to increase fitness (and the level of that increase). It also depends on the fatigue created by the same amount of load and the time of recovery (recoverability). So for the best results (at the current point in an athlete’s career), you need to find the optimal workload to produce optimal adaptation while allowing optimal recovery from the same!

Thus, you need to use a minimal load to provide adaptation and fast recovery. If you use larger loads, the fitness will increase more, but it will take more time for fatigue to decline and you’ll have fewer effects. You should search for optimal loading protocols for a given athlete at a given point in an athlete’s career. Note that relations are nonlinear!

The 3F model can explain all of the “modern phenomena” in training better than the dual factor (2F) or single factor (1F) models such as delayed fatigue, fatigue accumulation, facilitation, and unloading needs. Because of the interactions of fitness, fatigue, facilitation, and “energy adaptation drain,” it can be pretty simple to understand the superiority of the conjugate sequence system and the fight of various traits (e.g. strength and speed) for the same adaptation energy!

Single versus dual factor model of adaptation

(Mladen Jovanović, August 10, 2006)

The single factor model of adaptation depicts preparedness (or a single characteristic, ability, or trait) as a single line. After the training stimulus, preparedness decreases. Then, after some time, it “supercompensates” and returns to a normal level and beyond. So, it’s also called the “supercompensation” model. The larger the stimulus, the larger the decrease and thus, supercompensation.

I don’t know how over time people equated the dual factor model with fatigue accumulation (and the provocation of delayed adaptation). The dual factor model and fatigue accumulation approaches to training to produce delayed adaptation are not synonymous! Fatigue accumulation can also be explained by the single factor model and depends on the stimulus strength and frequency.

Fatigue accumulation results in a decrease in preparedness from the starting point and can be explained using both models. This method is proposed by Verkhoshansky. To be honest, I don’t buy it! Let’s take the sprint as an example. Your athletes should sprint without full recovery between sessions, and their performance should decrease over time. You then unload them and wait for the “miracle” to come (long-term delayed training effects). Again, I don’t buy this training approach for speed, strength, or power events. Maybe it works for endurance…maybe.

So, during that “accumulation” period, the athletes’ form starts to suck, and they are more prone to injury. They are “learning” to run with poor form. Three words—avoid this approach! The dual factor model depicts preparedness as a “steady” component (fitness) or a “fast” component (fatigue). Preparedness at a given instant of time equals fatigue plus fitness level.

The dual factor model more precisely depicts what is going on and can explain the effect of the tapering and unloading period while the single factor model can’t because there is always some minimal fatigue level in athletes whether or not they tried to train when fully recovered. Thus, there can be an increase in preparedness (and thus performance) from training session to training session while there’s also an accumulation of some minimal level of fatigue. When we unload or taper, the fitness component is kept constant and that minimal level of fatigue decreases. Thus preparedness (and performance) jumps even more. This can be depicted by the dual factor model but not by the single factor model.

Ok, here it is in a nutshell:

1. Single and dual factor models both explain adaptation. However, the dual factor is younger and can explain some things better (like the unloading and tapering effects).
2. The dual factor model is NOT synonymous with the fatigue accumulation approach to training. Fatigue accumulation can be explained by both models.
3. Fatigue accumulation sucks! Preparedness (visible as performance) should become better, not worse over time. Sprinters should run faster. Lifters should lift heavier. Jumpers should jump higher/longer over time, not worse over time. Fatigue accumulation is “playing with fire.” Fire is useful, but it can burn!
4. Do NOT equate the conjugate sequence system with fatigue accumulation! Training blocks of unidirectional loading are done with elite athletes to provide the adaptation effect while maintaining all other previously developed traits. This is a must because elites athletes don’t respond very well to the sequential approach (one trait at a time) because of the “use it or lose it” law. In addition, they don’t respond well to the concurrent approach (all traits at one time) because they can’t respond to a large number of different stimuli (they get pretty fatigued). The solution is to emphasize the development of one single particular trait while maintaining all necessary, previously developed ones. This doesn’t necessarily mean fatigue accumulation. During unidirectional loading, the performance should go up, not down!
5. Although preparedness and thus performance go up, a certain amount of fatigue is accumulated over time (though it’s pretty low). This is why unloading and tapering increase performance before competition. Reduced volumes of training allow fatigue levels to decrease while maintaining the fitness component. The result is an increase in performance. This is easily explained by the dual factor model but not so well with the single factor model.
6. Unloading and tapering aren’t only done to decrease fatigue. Unloading is also done to allow various traits/abilities to “synchronize” because of their heterochronic characteristics. Also, it fills the CAR, which is “depleted” by preceding adaptations (that “spent” it). Unloading allows for a “waving” progression, which is one of the training principles. You can’t break principle laws. You can only break yourself on them.
7. I’m not crazy, but I spent four hours drawing this. I enjoyed it but really I should get a life!

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