Neural plasticity is a two-way street: Counteracting age-related neural deterioration with strength training.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing mechanistic and intervention literature without systematic review methodology.
PubMed 42134199 · doi:10.1016/j.archger.2026.106292
What was done
Narrative review synthesizing literature on how aging and resistance exercise impact the nervous system and force-generating capacity (maximal strength and rate of force development). The authors focused on studies using near-maximal or maximal testing contractions and stimulation protocols, and resistance training intensities exceeding 60% of maximal strength, evaluating both central mechanisms (corticospinal excitability, intracortical inhibition, central conduction velocity) and peripheral mechanisms (spinal alpha-motoneuron properties, peripheral conduction).
What was found
The abstract provides qualitative mechanistic syntheses without quantitative numbers or effect sizes. Efferent neural drive (motor unit recruitment and firing rate) was identified as a primary driver of both age-related force decline and training-induced recovery. Age-related increases in intracortical inhibition appear reversible with heavy strength training. In contrast, peripheral deficits (loss of spinal alpha-motoneurons, reduced motoneuron excitability, and decreased peripheral conduction velocity) showed negligible improvement with strength training. The authors concluded that improvements in efferent neural drive from heavy strength training stem predominantly from central nervous system adaptations rather than peripheral changes.
Why it matters
It highlights that age-related weakness is substantially neurogenic and indicates that maintaining or restoring neural drive requires heavy-load resistance training (>60% maximal strength) to drive central nervous system plasticity.
Limits
This is a narrative review with no study counts, participant numbers, or quantitative pooled estimates reported in the abstract. The authors explicitly note substantial methodological constraints in measuring corticospinal excitability and observe that structural brain changes are rarely evaluated directly alongside force-generating capacity, limiting precise localization of adaptations along the neural pathway.
Cited by
- supports Repeated practice and training improve the nervous system's ability to recruit neural resources necessary to perform the work.