Author(s): KENVILLE, R., BERKOW, S., RAGERT, P., MAUDRICH, T., Institution: LEIPZIG UNIVERSITY , Country: GERMANY, Abstract-ID: 1151

INTRODUCTION:
Athletic development centers on optimizing performance, including technical skills and fundamental motor abilities, e.g., strength and speed. Parameters such as maximum contraction force and rate of force development, influence athletic success, although performance gains become harder to achieve as athletic abilities increase 1. Non-invasive transcranial direct current stimulation of the cerebellum (CB-tDCS) has been used successfully to increase force production in novices 2, although the potential effects in athletes remain unexplored. The present study examined the effects of CB-tDCS on maximum isometric voluntary contraction force (MVCiso) and isometric rate of force development (RFDiso) during a bench press task in well-trained athletes.
METHODS:
21 healthy, male, strength-trained athletes (aged 25.6  3.7 years (mean  SD)) participated in a randomized, sham-controlled, double-blinded crossover design. Each participant completed an isometric bench press (iBP) task on two separate days, with at least 5 days between sessions, while receiving either CB-tDCS or sham stimulation (SH-tDCS). The anode (35 cm², current density: 0.057 mA/cm2) was placed over the bilateral cerebellum, with the cathode (reference; 100 cm², current density 0.020 mA/cm2) being placed on the right musculus buccinator. Current was administered either for 20 minutes (CB-tDCS) or ramped up for 30 s and maintained for 30 s before being ramped down for 30 s and terminated (SH-tDCS). Electromyography (EMG) recordings of three muscles involved in iBP were acquired bilaterally to uncover differences in neuromuscular activation and agonist-antagonist interplay between conditions.
RESULTS:
Contrary to our hypothesis, no significant differences in MVCiso and RFDiso were observed between CB-tDCS and sham conditions. Furthermore, no tDCS-induced differences in neuromuscular activation or agonist-antagonist interplay were revealed.
CONCLUSION:
Here, we argue that the effects of CB-tDCS on force production appear to depend on the individual’s training status. Future research should study individual differences in tDCS responses between athletes and novices, as well as the potential of high-definition tDCS for precise brain region targeting to potentially enhance motor performance in athletic populations.

REFERENCES:

1. Wernbom, M., Augustsson, J., & Thomeé, R. (2007). The influence of frequency, intensity, volume and mode of strength training on whole muscle cross-sectional area in humans. Sports medicine, 37, 225-264.

2. Kenville, R., Maudrich, T., Maudrich, D., Villringer, A., & Ragert, P. (2020). Cerebellar transcranial direct current stimulation improves maximum isometric force production during isometric barbell squats. Brain Sciences, 10(4), 235.