Multiple Sessions of Transcranial Direct Current Stimulation Combined With Squat Training Improve Lower-Limb Maximum...

Yan, X, Zuo, Z, Nitsche, MA, Zhang, X, and Qi, F. Multiple sessions of transcranial direct current stimulation combined with squat training improve lower-limb maximum strength in healthy adult men. J Strength Cond Res XX(X): 000-000, 2026-This study aimed to investigate the effects of transcranial direct current stimulation (tDCS) combined with Squat training (ST) on lower-limb maximum strength in healthy adult men. Sixty men (age: 21.6 ± 2.1 years, height: 177.5 ± 5.3 cm, body mass: 73.1 ± 7.4 kg) were randomly assigned to 4 groups (tDCS + ST group, sham tDCS + ST group, tDCS + rest group, sham tDCS + rest group). The 6-week intervention program was implemented with biweekly sessions, totaling 12 treatment sessions, each separated by a minimum 48-hour interval. After the tDCS intervention, the ST groups performed squat exercises while the tDCS + rest and sham tDCS + rest groups sat quietly for 30 minutes. Lower-limb maximal muscle strength was measured at 4 distinct time points: preintervention (T0), 24 hours post-third week intervention (T1), 24 hours post-sixth week final session (T2), and 1 week post-entire intervention completion (T3). Key evaluation metrics were measured, including 1 repetition maximum (1RM) squat, knee extensor and flexor peak torque, and rectus femoris cross-sectional area (CSA). Significant improvements in 1RM, knee extensor strength, and nondominant rectus femoris CSA were observed in both tDCS + ST and sham tDCS + ST groups compared with the sham tDCS-only group (p < 0.05). No differences in knee strength, 1RM, or rectus femoris CSA were observed between the tDCS + rest and sham tDCS + rest groups. The results indicate that anodal tDCS combined with ST does not yield additional training benefits on lower-limb maximal strength in healthy adults when compared with ST alone.