Purpose: The current study assessed the effect of acute moderate-intensity continuous exercise (MICE) performed under normobaric hypoxia, simulated at an altitude of 4000m on cognition, compared to sea-level normoxia. Method: Forty healthy inactive women were recruited for this study. Executive functions were measured during the follicular stage via a Go/No-Go task before, during and after 10-min cycling with 45% peak power output (PPO) under (1) normoxia (PIO2 = 150mmHg, FIO2 = 0.21), and (2) normobaric hypoxia (PIO2 = 87mmHg, FIO2 = 0.12). Reaction time (RT), accuracy rate (ACC), heart rate (HR), ratings of perceived exertion (RPE), and peripheral oxygen saturation (SpO2) were collected before, during and after the exercise. Results: RT (p < .001, partial η2 = 0.255) decreased but no changes were found in ACC (p = .179, partial η2 = .041) during MICE when compared with at rest. Hypoxia appeared to show a trend for improving cognitive function (p = 0.054, partial η2 = 0.082). Conclusion: At the same time of the menstrual cycle, and with similar daily energy intake and physical activity, MICE improves cognitive function in inactive young women, and short-term severe hypoxia simulated at 4000m altitude tends to ameliorate cognitive function. Acute MICE under severe hypoxia does not offset the benefits of exercise on cognitive function.