Fig. 2.

The responses commonly used to assess the site of neural adaptation to resistance training. Early studies have shown increased responses to percutaneous mixed nerve stimulation during a contraction following resistance training (e.g., Sale et al. 1983; Aagaard et al. 2002)—these responses are known as the H-reflex (a), which is a long-latency response to submaximal nerve stimulation often evoked with a small M-wave (note the short-latency response), and the V-wave (b), which is a long-latency response to supramaximal nerve stimulation (hence the presence of a short-latency maximal M-wave; for further details on methodology see Burke and Gandevia 1999). In recent decades, transcranial magnetic stimulation (for details on methodology see Rossini et al. 2015) has been used to infer the site of neural adaptation to resistance training; however, the response to such stimuli, known as the motor evoked potentials followed by the silent period (c), have yielded variable results when assessed after resistance training (for meta-analysis see Siddique et al. 2020). Since responses to transcranial magnetic stimulation alone cannot differentiate between the cortical and spinal site of adaptation, additional methods have had to be employed, such as responses to direct activation of corticospinal axons, e.g., lumbar evoked potentials (d), but they have been shown not to change following resistance training (Nuzzo et al. 2017; Ansdell et al. 2020). It is important to note that changes in responses to stimulation techniques following resistance training are likely to be specific to the training task (Kalmar 2018)—as a result there have been recent attempts to replicate the training task when assessing responses to stimulation (E; from Brownstein et al. 2018, with permission). Data displaying responses is from the personal archive of the authors—the average of 5 responses is displayed in colour with individual response overlaid in black