Objective: Brain responses during exercise are rarely studied because movement limits imaging techniques. With the develop-ment of functional near-infrared spectroscopy (fNIRS), it is assumed that the change in brain oxygenation could be accepted as a change in brain haemodynamics. In terms of exercise studies, aerobic exercise was the main topic. However, isometric exercise significantly increases body wellness, and therefore it began to be a suggested exercise model, especially for the elderly popu-lation. Despite these physiologic effects, the haemodynamic effects of isometric exercise in the brain remained unknown. The aim of this study was to show the brain haemodynamic changes during isometric exercises.Methods: Seven healthy males (mean age: 24.71±3.33 years), who trained regularly, were enrolled in the study. fNIRS measurements were recorded from the forehead, where prefrontal cortex activity is reflected. The participants underwent three different exercises: handstand, squat, and plank. The oxygenation levels collected from the pre-, during-, and post-exercise conditions were evaluated.Results: According to the fNIRS results, brain oxygenation in the prefrontal cortex increased during exercise in all positions (p<0.05). Additionally, the post exercise oxygenation values were observed higher than the pre-exercise conditions.Conclusion: Haemodynamic changes during isometric exercise have been shown in this study. Brain oxygenation was in-creased during isometric exercise. In future studies, the brain haemodynamics of positional changes could be investigated as a factor to determine the positional effect during exercises. Also, the cognitive effects of isometric exercise could be a future research topic.