Resistance training induces supraspinal adaptations: evidence from movement-related cortical potentials

Abstract

Early effects of a resistance training program include neural adaptations at multiple levels of the neuraxis, but direct evidence of central changes is lacking. Plasticity exhibited by multiple supraspinal centers following training may alter slow negative electroencephalographic activity, referred to as movement-related cortical potentials (MRCP). The purpose of this study was to determine whether MRCPs are altered in response to resistance training. Eleven healthy participants (24.6 +/- 3.5 years) performed 3 weeks of explosive unilateral leg extensor resistance training. MRCP were assessed during 60 self-paced leg extensions against a constant nominal load before and after training. Resistance training was effective (P < 0.001) in increasing leg extensor peak force (+22%), rate of force production (+32%) as well as muscle activity (iEMG; +47%, P < 0.05). These changes were accompanied by several MRCP effects. Following training, MRCP amplitude was attenuated at several scalp sites overlying motor-related cortical areas (P < 0.05), and the onset of MRCP at the vertex was 28% (561 ms) earlier. In conclusion, the 3-week training protocol in the present study elicited significant strength gains which were accompanied by neural adaptations at the level of the cortex. We interpret our findings of attenuated cortical demand for submaximal voluntary movement as evidence for enhanced neural economy as a result of resistance training.

Conflict of interest statement

Conflict of interest statement The authors declare that they have no conflict of interest.

Figures

Fig. 1

Illustration of experimental setup

Fig. 2

MRCP amplitude measures (μV), Note: Amplitudes for each component before (black) and after (gray) training. Error bars are standard deviation. Hotelling t2: †P < 0.05; Paired t test: **P < 0.01, *P < 0.05

Fig. 3

2D topographical maps of component amplitudes, Note Each map is oriented such that the anterior–posterior axis is arranged vertically (i.e. nasion is located at the top)

Fig. 4

Grand average waveforms of MRCP and multi-channel display. Note Grand average waveforms are presented for Cz, C1, and C2 both before (black) and after (gray) training. Dashed line represents the onset of movement. Multiple electrode sites around those of interest (e.g. Cz, C1, C2) are also displayed