The fitness-fatigue model posits that if fitness increases at the same rate as fatigue, performance may not improve, necessitating fatigue reduction to actualize training adaptations.

“what I think about it is understanding what we call the fitness fatigue model so what I mean by that is whenever you do some sort of insult the whole idea is for you to come back and get an adaptation now recovery is not adaptation right recover is recovery adaptation is what happens after you're recovered right so there's a very important distinction there Fitness fatigue model says basically you've done something and you've got an adaptation and you've enhanced Fitness and by Fitness in this case I mean it as a non-specific term so you got stronger you've uh improved your endurance like whatever thing you're trying to train for at the same time though your fatigue elevated so what happens is if Fitness increases at the same or similar rate as fatigue your performance actually isn't any better and so you may think oh my program isn't working I need to then train harder or need to take more anti-inflammatory or whatever the things are when in reality all you really need to do is reduce fatigue and if you do that your performance will increase and all the training adaptations will be actualized”