Strength Training with Superimposed Whole Body Vibration Does Not Preferentially Modulate Cortical Plasticity

Paired-pulse transcranial magnetic stimulation (TMS) was used to investigate 4 wks of leg strength training with and without whole body vibration (WBV) on corticospinal excitability and short-latency intracortical inhibition (SICI). Participants (n = 12) were randomly allocated to either a control or experimental (WBV) group. All participants completed 12 squat training sessions either with (WBV group) or without (control group) exposure to WBV (f = 35 Hz, A = 2.5 mm). There were significant (P < 0.05) increases in squat strength and corticospinal excitability and significant (P < 0.05) reductions in SICI for both groups following the 4 wk intervention. There were no differences detected between groups for any dependant variable (P > 0.05). It appears that WBV training does not augment the increase in strength or corticospinal excitability induced by strength training alone

Strength training reduces intracortical inhibition

Aim: Paired-pulse transcranial magnetic stimulation was used to investigate the influence of 4 weeks of heavy load squat strength training on corticospinal excitability and short-interval intracortical inhibition (rectus femoris muscle). Methods: Participants (n = 12) were randomly allocated to a strength training or control group. The strength training group completed 4 weeks of heavy load squat strength training. Recruitment curves were constructed to determine values for the slope of the curve, V50 and peak height. Short-interval intracortical inhibition was assessed using a subthreshold (0.7 × active motor threshold) conditioning stimulus, followed 3 ms later by a supra-threshold (1.2 × active motor threshold) test stimulus. All motor evoked responses were taken during 10% of maximal voluntary isometric contraction (MVC) torque and normalized to the maximal M-wave. Results: The strength training group attained 87% increases in 1RM squat strength (P &amp;lt; 0.01), significant increases in measures of corticospinal excitability (1.2 × Motor threshold: 116%, P = 0.016; peak height of recruitment curve = 105%, P &amp;lt; 0.001), and a 32% reduction in short-interval intracortical inhibition (P &amp;lt; 0.01) following the 4-week intervention compared with control. There were no changes in any dependent variable (P &gt; 0.05) detected in the control group. Conclusion: Repeated high force voluntary muscle activation in the form of short-term strength training reduces short-interval intracortical inhibition. This is consistent with studies involving skilled/complex tasks or novel movement patterns and acute studies investigating acute voluntary contractions. © 2012 The Authors Acta Physiologica © 2012 Scandinavian Physiological Society

The cientificWorldJOURNAL Research Article Strength Training with Superimposed Whole Body Vibration Does Not Preferentially Modulate Cortical Plasticity

Paired-pulse transcranial magnetic stimulation (TMS) was used to investigate 4 wks of leg strength training with and without whole body vibration (WBV) on corticospinal excitability and short-latency intracortical inhibition (SICI). Participants (n = 12) were randomly allocated to either a control or experimental (WBV) group. All participants completed 12 squat training sessions either with (WBV group) or without (control group) exposure to WBV ( f = 35 Hz, A = 2.5 mm). There were significant (P &lt; 0.05) increases in squat strength and corticospinal excitability and significant (P &lt; 0.05) reductions in SICI for both groups following the 4 wk intervention. There were no differences detected between groups for any dependant variable (P &gt; 0.05). It appears that WBV training does not augment the increase in strength or corticospinal excitability induced by strength training alone