Transcranial Stimulation Improves Volume and Perceived Exertion but does not Change Power

Abstract

This study aimed to analyze the acute effect of anodal transcranial direct current stimulation (a-tDCS) over the primary motor cortex (M1) on the volume, perceived exertion, and neuromuscular performance measurements in trained and untrained adults. Twenty-four male adults (12 trained and 12 untrained) participated in this single-blind, randomized, and sham-controlled study. The participants performed three back squat repetitions using the 15RM load with maximal concentric velocity to assess neuromuscular performance before tDCS and 30-min after resistance exercise. Next, they were randomly assigned to a-tDCS over M1 or the sham condition. Participants performed ten sets of parallel back squat with 15RM load and repetitions sustained to momentary muscular failure. The total number of repetitions was higher (p<0.05) and perceived exertion was lower (p<0.05) after a-tDCS in both groups. Peak power, velocity, and force decreased in both groups after the RE session (p<0.05), but with a higher rate in untrained individuals (p<0.05). No significant effect was found for peak power, peak velocity, and peak force (p>0.05). This study suggests that using a-tDCS may improve the total volume of repetitions and perceived exertion in trained and untrained individuals.

A Single Anodal Transcranial Direct Current Stimulation Session to Enhance Sport-Specific Performance in Trained Individuals? A Systematic Review and Meta-Analysis

“…Sample sizes of included studies ranged from 8 to 36 participants (13.6 ± 6.6). Athletes were experienced in various sports disciplines: cycling [16, 29, 35, 36, 41], swimming [37, 39, 43], triathlon [30], rowing [41, 42], bodybuilding [31], resistance training [38], basketball [40], parkour [3], taekwondo [17, 32] and pistol-shooting [33]. Additionally, some studies reported that athletes competed at the regional [39], national [17, 32, 37, 42, 43] and/or international level [17, 30, 32, 37].…”

“…For an overview of investigated sport-specific motor performances in each study, please see Table 1. Sport disciplines were categorized in the following performance domains: endurance (cycling [16, 29, 35, 36, 41], swimming [37, 39, 43], triathlon [30], rowing [41, 42]), strength (bodybuilding [31], resistance training [38]) & visuomotor skill (basketball [40], parkour [3], taekwondo [17, 32], pistol-shooting [33]).…”

“…All studies applied tDCS prior to sport-specific performance. Cortical target areas of tDCS were clustered in 4 groups: M1 [3, 17, 30-32, 34, 38, 40-42], TC [29, 31, 43], PFC [3, 16, 35-37, 39] and CB [33]. Current intensity was set at 2 - 2.2 mA in most studies (78 %) or 1.5 mA (22%).…”

“…Our results corroborate this heterogeneity for sport-specific performance in athletes. Among the ten included studies that stimulated M1, five showed performance-enhancing effects [3, 31, 38, 40], whereas the remaining five studies failed to demonstrate any behavioral effects [17, 30, 32, 41, 42]. On a functional level, anodal tDCS over M1 has been shown to increase the excitability of M1 [4], which improves the neural drive to the working muscles [51].…”

“…In addition, a Google Scholar search identified one study that was not indexed in the searched databases because of its recent publication date. Finally, a total of 18 studies were deemed eligible for inclusion in the qualitative synthesis [3,16,17,[29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. An overview of the study selection process is depicted in the PRISMA flow diagram (Figure 1).…”