The Acute Effect of Post-Activation Potentiation with Transcranial Random Noise Stimulation on Some Electrophysiological and Functional Variables of Athletic Men

The present study investigated the effect of combined post-activation potentiation (PAP) and transcranial random noise stimulation (tRNS) on maximal muscle activity in maximum voluntary isometric contraction test (MVIC) and integrated electromyography (IEMG) when knee extension was kept on the leg extension machine. 10 athlete students from wrestling, track and field and volleyball with mean age of 29/1 years performed one of four protocols that included usual warm-up plus sham tRNS (control group), usual warm-up plus tRNS, usual warm-up plus performing a set of right leg extension (80% of 1 repetition maximal) on the leg extension machine and usual warm-up plus tRNS plus a set of right leg extension in four separate sessions which occurred 24 hours after each other. The brain waves activity levels and electromyogram activity of vastus lateralis, rectus femoris and vastus medialis muscles were recorded simultaneously by using electroencephalography and electromyography respectively when the subjects performed were performing the test. The results showed a significant increase in the absolute power of all three brain waves in the Cz channel for every three conditions of the post-test compared to the pre-test during both MVIC (P=0.001) and keeping leg extension tests on leg extension machine(P=0.001). The amounts of maximum muscle activity for MVIC test and muscle IEMG values during keeping leg extension on the leg extension machine showed a significant increase in every three post-test conditions compared to the pre-test for all muscles (P=0.001). The duration of keeping leg extension on the leg extension machine was significantly increased for every three post-test conditions compared to the pre-test (P=0.001). It seems applying of tRNS and PAP, and also combined use of them after warm up can increase brain activity, maximum muscle activity, integrated electromyography and the duration of keeping leg extension in both tests compering to just warm up. Ultimatly, combined use of tRNS and PAP has an impressive effect compared to applying them separately.