Do heavier loads cause greater CNS fatigue than lighter loads ?

Do heavier loads cause greater CNS fatigue than lighter loads ?

It may kind of feel intuitive to assume so, in fact it’s quite common to think that “heavy loads” “fry your CNS!”

But is that correct ?

CNS Fatigue is something measurable, and it can be defined as the inability to produce force by a given muscle, due to a reduction in neural drice force caused by many factors.

If it lasts for several days, it’s actually more related to peripheral factors, such as muscle fiber damage, following hard, long-lasting contractions, which are more likely to occur in light-weight “resistance type” training.

This can hinder progress if the program is hypertrophy-oriented, because not being able to tap into high-threshold motor units means simply not making the training as effective as it should be.

For this reason, keeping the loads on the heavier side (for most exercises) can help us maximize the mechanical tension on the muscle fibers, while accumulating less fatigue.

As always, working within optimal training guidelines will be paramount when training for hypertrophy!