Effects of a single session of tDCS on upper and lower limb strength in recreationally resistance-trained young men: a randomized crossover pilot study

Aims: Studies have focused on transcranial direct current stimulation (tDCS) for therapeutic purposes and physical performance. However, little is known about its role in strength and resistance. This study tested the hypothesis that tDCS increases maximal and resistance strength in recreationally resistance-trained subjects. Methods: A randomized, crossover, double-blinded study was conducted on fifteen young trained men (18–26 years). All subjects received either a single tDCS session or Sham over the M1 area for 20 min. After stimulation, subjects were submitted to evaluation of maximum strength capacity (3 sets of one repetition maximum (1RM) at 85%) and resistance (3 sets of 1RM at 50%) in Leg Extension (LE) and Elbow Flexion (EF) exercises. Results: Linear mixed models analysis showed a significant main effect for sets in all situations: LE85 p < 0.001, EF85 p < 0.001, LE50 p < 0.001, and EF50 p < 0.001. Regardless of tDCS, a reduction in repetitions was observed in the final sets of LE85 and EF85, but there was no interaction between factors and no differences between groups. Conclusion: A single tDCS session does not promote positive changes in strength or resistance capacity of healthy young trained men.