Elite Cyclists with type 1 diabetes show acceptable glycemic excursions during a time-trial performance under high-definition transcranial direct-current stimulation

Background: Patients with type 1 diabetes (T1D) often face glycemic fluctuations during exercise. HD-tDCS, known for enhancing neuromodulation focus, has shown promise in improving endurance. Objective: To evaluate the effects of bilateral dorsolateral prefrontal cortex HD-tDCS on glycemic excursions during a time-trial performance in elite cyclists with T1D. Methods: In a double-blind, randomized crossover order, nine elite cyclists with T1D (no complications) underwent either HD-tDCS (F3, F4) or control (SHAM) and completed a constant-load trial at 75% of the 2nd ventilatory threshold plus a 15-km cycling time-trial. Results: Real-time continuous glucose monitoring revealed similar glycemic variability between the two conditions, showing a significant effect of time but no interaction (stimulation x time) or stimulation effect. Conclusions: As glycemic control is crucial for both health and performance, these findings suggest that HD-tDCS could be safely used to enhance performance in athletes with T1D, and potentially in a broader active T1D population.