Fitness Fatigue Model

Noah Syndergaard training under Josh’s watchful eye at the Original Metroflex Gym.

What’s the difference between Virginia and West “By God “Virginia? In Virginia, Moosehead is a beer. In West Virginia, it’s a misdemeanor!


Similarly, did you know the exact same amount of total volume in training can have a completely different training effect on the same lifter—that brings us to the fatigue model.  

What exactly is the Fitness Fatigue Model?

The Fitness Fatigue Model looks at the long-term after effect from a training stimulus.

 The after effect will cause an increase in one-rep max (1RM) squat max, such as after a powerlifting peaking cycle of squats. The increased 1RM is the fitness component. The fatigue effect is the short-term after effect from training stressors; multiple sets of heavy squats will cause fatigue.

Significant delayed onset of muscle soreness (DOMS) is a prime example of fatigue. Fabled sprint coach, the late Charlie Francis, at his seminars used to say that the CNS is like a cup of tea that you must never let overflow. 

Every stressor, whether it’s personal problems, interval training, weight training, or lack of sleep, adds tea (in this case fatigue) to your cup. If the cup of tea (fatigue) does not overflow but is adequately stressed, supercompensation (fitness) takes place.

Strength training “volume” is a product of poundage lifted multiplied by repetitions, multiplied by sets. If an athlete with a maximum bench press of 300 pounds executed  three different workouts on the bench press, he would also produce different amounts of fatigue and ultimately fitness.  Workout 1 might be 230 pounds x 3 x 8 sets, primarily neural adaptations will take place; if he does 230 pounds x 8 x 3 sets, more hypertrophic response will be induced; if he does 50 pounds x 24 reps x 3 sets, this will be more of a flushing workout, facilitating an active recovery response.

All three of these set-and-rep schemes will produce a totally different hormone and neuromuscular response, along with inducing fatigue and gaining fitness during supercompensation, yet each workout is 5,520 pounds of total volume.

The GAS Principle looks at total work as the sole variable to influence fitness response from training, whereas the Fitness Fatigue Model expands on this simplistic outlook by taking into account not only total volume, but the intensity/magnitude of training stimuli. Walking two miles is different than sprinting eight quarter miles, even though total volume is the same.

Each individual training variable is independent of the others, but their total summation will equate to total fatigue produced and total specific fitness gained. If too much fatigue is induced, over time a cumulative “snowball” effect will take place.  The initial phase is called overreaching, which may, in fact, be your immediate desired result, so fitness gains can take place during a period of decreased volume/intensity; but if this goes beyond overreaching to the point of overtraining, it can take months to recover.

Periods of significant fatigue followed by significant recovery produce significant results! Different training methods and stimuli trigger different responses. This is especially true for more advanced tactical athletes.

After stressful training, a period of lower volume and less intensity (deload/reload) is required for optimal performance. To gain the positive fitness effects after a period of stressful overreaching, a period of less volume/ intensity is called for to eliminate fatigue aftereffects and get the desired training effect.

In 1995, in his book, Science and Practice of Strength Training, Vladimir Zatsiorsky stated that in a workout of average intensity, the fitness effect endures roughly three times longer than the fatigue effect. That means, if the fatigue aspect from a training session dissipated after two days, fitness gains will persist for six days.

The fitness fatigue model doesn’t replace (GAS) or the 7 Grandaddy laws but expands on them.

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