Purpose <p>Electrical muscle stimulation (EMS) is increasingly explored as a strategy to potentially enhance cerebrovascular and cognitive health, offering an alternative to voluntary exercise. While previous studies indicate that EMS can increase cerebral blood flow velocity (CBFv), its cognitive effects remain inconsistent. Furthermore, lower-limb EMS is typically delivered as simultaneous bilateral or unilateral stimulation, and the cerebrovascular impact of alternating unilateral stimulation, has not been investigated. This proof-of-concept study examined the effects of two quadriceps EMS patterns, simultaneous bilateral stimulation (SIM-EMS) and alternating unilateral stimulation (ALT-EMS), on CBFv and cognitive performance in healthy young men.</p> Methods <p>Fifteen participants completed two randomized 25-minute EMS sessions at maximal tolerable intensity. Continuous monitoring included right middle cerebral artery velocity (MCAv), left posterior cerebral artery velocity (PCAv), mean arterial pressure (MAP), heart rate, and end-tidal CO₂ (PETCO₂). Cognitive performance was assessed pre- and post-session using the Stroop Color Word Test (SCWT) and Trail Making Test (TMT).</p> Results <p>Both EMS patterns significantly increased MCAv (~5-6%), MAP, heart rate, and PETCO₂, whereas PCAv remained unchanged. Cognitive outcomes improved after both sessions. Despite higher electrically evoked torque during SIM-EMS, no differences in cerebrovascular or cognitive responses were observed between the two stimulation patterns.</p> Conclusion <p>These findings suggest that even a single EMS session can acutely enhance anterior cerebral perfusion and cognitive performance in healthy young adults, independent of stimulation pattern. Alternating unilateral EMS may therefore offer an alternative modality to traditional bilateral protocols without compromising cerebrovascular or cognitive benefits.</p>