Rep Speed Slow or not

“So, when reps move slow and are close to failure, they trigger the series of events that lead to hypertrophy, but if reps are slow due to Neural fatigue.. they hinder this process ? How can we tell which one is which ? *Confused*.”⁣. ⁣⁣
⁣⁣
Basically, in both scenarios, reps require high levels of effort to be completed: and (if you’ve been following my content!) you should know that reps that require a lot of effort will move at a slower speed because of the Force-Velocity relationship (which we’ve seen in previous posts)… but then why does one promote hypertrophy and the other doesn’t, if both move slow ? ⁣⁣
⁣⁣
The answer is motor unit recruitment, and the force/tension that each fiber exerts (..and experiences!). ⁣
⁣
When we’re lifting in a fatigued state (Experiencing CNS fatigue) our ability to recruit high threshold motor units is hindered, therefore the amount of force we can produce is lower. This makes even “lighter” weight or the beginning of a lighter set require more effort than usual. The number of motor units recruited is limited, hence the reason why we’re not feeling “as strong” as we should feel.⁣
⁣⁣
On the other hand, lifting in a non-fatigued state will allow us to recruit all the motor units available, depending on how much effort we need to exert – which in the case of a set taken to failure – will mean all of the available ones. ⁣⁣
Basically, when we start the set the reps move fast and only slow down as we’re approaching failure.⁣⁣
⁣⁣
In fact as we know, if our goal is hypertrophy, reps need to satisfy 2 important conditions for our repetitions to “matter”. There needs to be:⁣⁣
⁣⁣
(1) Full motor unit recruitment⁣⁣
(2) A slow contraction speed⁣⁣
⁣⁣
And only the “non-fatigued” scenario is able to get to both at the same time! ⁣⁣