Figure 3

Experimental design and timeline, tDCS montage, and cycle ergometer with cognitive test set-up. The upper part shows the computational model of the electric field (||E||) acting on the left DLPFC of the participants during anodal and cathodal tDCS (Neuroelectrics Instrument Controller version 2.0.10, Neuroelectrics, Barcelona, Spain). The middle part shows the experimental timeline comprising the intervention (EXP. 1: a-tDCS alone, EXP. 2: c-tDCS alone, EXP. 3: AE alone, EXP. 4: a-tDCS during (d) AE and EXP. 5: c-tDCS during AE) and control conditions (EXP 1.: s-tDCS alone, EXP. 2: s-tDCS alone, EXP. 3: Active control (AC), EXP. 4: s-tDCS during AE and EXP. 5: s-tDCS during AE). Active control (AC) was applied in all control conditions, which means that even during s-tDCS, all participants sat on the cycle ergometer and cycled with a very low intensity of 15 Watts. The lower part shows the cycle ergometer with 1) the control monitor displaying to the investigator the heart rate, pedal cadence, and Watt; 2) the task screen where the cognitive tests were presented during cycling; and 3) the response buttons (The Black Box Toolkit) fixed at the steering of the ergometer, enabling participants to easily make responses by button presses without changing posture. Cycle ergometer drawing was done using the software SketchUp.