Neural Edge

In classic strength & conditioning terms, reps and sets have numerical values:

3 sets x 10 reps

5 sets x 5 reps

1 set x 20 reps

These numbers represent the volume of work to be completed, as well as implying the intensity the work should be completed at. For example 3 sets x 10 reps equals 30 reps total volume, whilst 10 reps implies using a relatively light weight. 5 sets x 5 reps on the other hand represents 25 reps of total volume, with 5 reps suggesting that those 25 reps should be much harder than the 30 reps of 3x10.

This is all about driving specific physiological adaptations using exercise, with 5x5 more likely to drive peak force / strength gains, and something like 3x10 more likely to drive muscular endurance and hypertrophy improvements (depending on the individual).

But what about if the adaptation we’re chasing is neurological? Neuroplasticity is the brain and nervous systems ability to change in response to experience, and can be either adaptive (helpful) or maladaptive (unwanted). Neuroplasticity is incredibly specific, and the brain will only adapt to the stimulus you provide. So if you complete 3 sets x 10 reps of an exercise poorly, that’s what you’ll adapt to.

This is where I use the concept of ‘neural edge’ with my clients. If the chief concern is how they’re performing an exercise, I don’t really care how many reps they do. I care more about the quality of those reps. The problem is that if I just told them to complete 3x10 of every exercise I gave them, 3 of those reps might fall within the bandwidth of acceptable competence we’re looking for, but the remaining 7 might reinforce habits we’re trying to undo. In this case 30% of the reps were adaptive, but 70% were maladaptive, leading to a net-unproductive set.

Instead, I often tell them to complete as many reps of the exercise as they can do with good quality, but to stop the set as soon as quality starts to drop off. This might be 2 reps. It might be 15. It doesn’t matter to me. What matters is that we’re driving adaptive neuroplasticity and creating the changes we need to make in order to achieve the individual's pre-define goals. Over time, I expect to see the number of reps they can perform well, their ‘neural edge’, increase as their nervous system adapts and learns the new skill.

This was illustrated perfectly today with a new MS client I was working with on their footdrop when during some seated dorsiflexion work, they were only able to complete 2 reps before their foot started to primarily invert. So we did 5 sets of 2 reps yesterday, but upon returning for her second session today this number had gone up to 7. That’s neuroplasticity in action. If we had just done 3x10 reps yesterday, 24 of those total 30 reps would have been maladaptive, reinforcing the exact pattern we were trying to undo.

Don’t get me wrong, there’s a time and a place for set rep prescriptions. I use them all the time. But when the primary aim is to drive adaptive plasticity and learn a new skill, 10 reps for one person might be well within their ‘neural edge’, whilst being far outside of it for another. This is where individualisation in rehab becomes key to creating the changes you want to make, rather than assuming that age old dogma will apply to everyone.