Reductions in cerebral blood flow (CBF) and poor vascular control are associated with increased risk of stroke and neurodegenerative disease (e.g. vascular dementia, Alzheimer’s)(1). Recently, research initiatives have been initiated to examine sex-specific cerebrovascular regulation due to observations of differing expressions and treatment responses to cognitive and vascular diseases between Women (WN) and Men (MN)(2). Within this context, exercise is a promising non-pharmacological intervention to help combat cerebrovascular dysfunction(3). Previous research has shown differing vasodilator responses to both handgrip and knee extensor exercise in healthy WN and MN (4-5). Despite, these observations, the vast amount of research investigating CBF responses to exercise in humans have been conducted in men at lower exercise intensities. It is unknown if the sex differences in vascular response to exercise observed in the periphery exist in the brain. PURPOSE: Therefore, the aim of our pilot study was to compare CBF and cerebrovascular conductance index (CVCi) – Exercise Intensity relationships between MN and WN. METHODS: 10 healthy adults (5 WN, 24 ± 4.1 yrs) completed a graded-exercise-test (GXT, stage length 3-min, 50W, 75W, 100W; after which MN increases by 40W, WN increased by 30W) on a recumbent cycle ergometer to volitional exhaustion (unable to maintain RPM of 60-80). Maximal Wattage (Wmax) was determined to be the wattage of the highest completed stage. Middle cerebral artery velocity a proxy of CBF (MCAv; transcranial Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography), were measured on a beat-by-beat basis to calculate CVCi = MCAv/MAP. RESULTS: mean ± S.E.M. Peak MCAv were similar between WN & MN (82.3 ± 4.6 cm/s vs. 81.9.5 ± 4.8, p = 0.94). However, WN reached their peak MCAv at a lower relative exercise intensity (41.9 ± 3.1 vs. 61.6 ± 6.5 %Wmax, p ≤ 0.05). WN & MN did not differ in CVCi (0.69 ± 0.1 vs. 0.73 ± 0.09 cm/s/mmHg, p = 0.5 ) at the %Wmax where peak MCAv was achieved. CONCLUSION: WN achieve peak MCAv at a lower relative exercise intensity than MN. However, there appears to be no sex difference in vasodilatory responses to graded exercise as there was no difference in CVCi at peak MCAv. Thus, while the CBF – Exercise Intensity relationship differs between the sexes, evidence for a greater exercise vasodilatory response to exercise in brain of WN, as observed in other circulations, is not apparent.