Rui Miguel Silva

Objective: This study investigated the synergistic effects of neurofeedback (NF) and transcranial direct current stimulation (tDCS) on enhancing athletic performance and psychological resilience in elite athletes, addressing critical gaps in standardized protocols and long-term efficacy within sports neuroscience. Methods: A randomized, double-blind, sham-controlled crossover design was employed with 60 national-level athletes (30 male, 30 female) stratified by sport type (endurance/skill-based). Participants underwent 10 sessions of either: (1) active NF (SMR upregulation via 64-channel EEG) + active tDCS (2mA over left DLPFC), (2) active NF + sham tDCS, (3) sham NF + active tDCS, or (4) sham NF + sham tDCS. Primary outcomes included sport-specific performance metrics (reaction time, time-to-exhaustion) and psychological resilience (CD-RISC-25), with secondary EEG measures (beta power, P300) assessed at baseline, post-intervention, and 8-week follow-up. Results: The combined NF+tDCS group demonstrated superior improvements versus sham controls: 15.2% faster reaction time (p < 0.001, d = 1.21), 12.4% increased endurance (p = 0.002), and 22.3-point higher resilience scores (p < 0.001). EEG revealed sustained beta power elevation over the left DLPFC (+2.1 dB at follow-up, p = 0.01), mediating 41% of resilience gains through reduced amygdala reactivity (HRV analysis, β = 0.64, p = 0.003). Skill-based athletes showed greater cognitive benefits, while endurance athletes exhibited stronger psychological gains, with sex-specific effects noted (females: better tDCS response; males: superior NF anxiety reduction). Conclusion: Combined NF and tDCS induces durable, sport-specific enhancements in both performance and resilience, likely through prefrontal-amygdala circuit plasticity. These findings advocate for personalized neuromodulation protocols in elite sports while highlighting the need for ethical frameworks governing neuroenhancement technologies.