Fatigue is probably one of my favorite topics of resistance training science, and although we know something about it, there's definitely a alot of room for new research to enlighten us here. ⁣

In today's post, I want to talk about whether or not it's a good idea to train while experiencing fatigue (mainly CNS fatigue). ⁣

Well, as you may have guessed, it's not a good idea to do so. Duh.... but why ? ⁣

Well, the reason behind it is actually very interesting! ⁣

When we train for maximal force production, and hypertrophy, we need to be able to perform repetitions with maximal intent & effort, in order to promote the adaptations that we're looking to get out of the training program:⁣

This means that the repetitions we perform for our training sets will have to feel hard and possibly move slow. ⁣

When this happens, all of our muscle fibers need to be recruited and need to contract forcefully in order to produce high levels of force to move the weight. ⁣

And that is pretty much what happens as we get close to reaching task failure within a set (point at which we can no longer perform any repetition without substantially deteriorating our technique) or lifting heavy weights in general. ⁣

What happens when we lift in a fatigued state ? ⁣

In this case, reps feel way harder than they should, even at lighter (than usual) weights. ⁣

They move slower than we'd like to, and we are not able to produce as much force as we used to. ⁣

This happens because when we are in a fatigued state, the ability of our brain to recruit high threshold motor units, is impaired, or at least reduced, so in a nutshell, we aren't able to recruit all the muscle fibers needed to exert high levels of force to move the weight. ⁣

This reduces our performance and doesn't allow us to make progress as we'd like to, and if over done (generally with too much training volume), it can seriously mess up with our progress, likely get us injured and definitely frustrated! ⁣