Can Transcranial Direct Current Stimulation Improve Muscle Power in Individuals With Advanced Weight-Training Experience?

Abstract

The aim of this study was to investigate the effects of transcranial direct current stimulation (tDCS) on countermovement jump performance (CMJ) in men with advanced strength training experience. Ten healthy male subjects, with advanced strength training and squatting exercise experience, were included. Participants took part in an initial visit to the laboratory to complete anthropometric measurements and CMJ kinematic test-retest reliability. Participants then completed three experimental conditions, 48-72 hours apart, in a randomized, double-blinded crossover design: anodal, cathodal and sham tDCS (2 mA for 20 minutes targeting the motor cortex bilaterally). Participants completed three CMJ tests before and after each experimental condition, with one-minute recovery interval between each test. The best CMJ in each moment was selected for analysis. Two-way (condition by moment) repeated measures ANOVA's were performed for CMJ height, flight time and muscular peak power. Effect sizes and interindividual variability of tDCS responses were also analyzed. There was a significant condition by moment interaction for all outcome measures, with a large pre-post increase in CMJ height, flight time and muscular peak power in the anodal condition. All the participants displayed CMJ performance improvements after the anodal condition. There were no significant differences in both cathodal and sham conditions. Anodal tDCS may be a valuable tool to enhance muscle power related tasks performance, which is extremely relevant for sports that require vertical jumping ability. Anodal tDCS may also be used to support strength training, enhancing its effects on performance-oriented outcome measures.

Effect of transcranial direct current stimulation on sports performance for two profiles of athletes (power and endurance) (COMPETE): a protocol for a randomised controlled trial.

“…Our sample size calculation is based on the primary efficacy outcome that relates to changes in motor performance before and after a tDCS session during an explosive task (jumps). In a previous study, Lattari et al [22] showed an 11.2% improvement in the performance of the CMJ following a tDCS session, with a standard deviation for paired-differences of 6.5. We expect a 15% improvement in our study due to an additional experimental session.…”

“…In fact, despite rare clues in the literature showing a positive effect on vertical jump performance [22], no studies really assessed the tDCS effects over such type of exercise and its associated mechanisms. Indeed, regarding the tDCS effects on physical tasks, the literature is more developed regarding endurance performance.…”

Executive functions, self-paced exercise and cycling performance

“…Robinson et al [42] asked nine active adults to match the 80% of a 3-min all-out test, during a 3-min cycling self-paced exercise by using an internal associative strategy or external dissociative strategy. They found that using an associative strategy, participants completed the test at their 75.9% of the average power output obtained in 3-min all-out test performance, whereas with the dissociative strategy participants were only able to achieve 70.9% of their performance.…”

“…They found that using an associative strategy, participants completed the test at their 75.9% of the average power output obtained in 3-min all-out test performance, whereas with the dissociative strategy participants were only able to achieve 70.9% of their performance. They argued that in novice participants, distracting the attention from performance can slow down the pacing, and therefore an internal (associative) focus strategy might help to maintain a more consistent performance throughout a self-paced event [42].…”

“…In conclusion, there are only a few self-paced exercise studies in which the attentional focus has been manipulated externally and the results are somewhat mixed. An associative strategy might increase RPE, but it might be mediated by an increased performance [39,42]. Yet, a dissociative strategy might improve exercise performance [40,42] without increasing RPE [41], at least in more proficient athletes.…”