Changes In Cerebral Blood Flow Velocity, Arterial Oxygen Saturation and Myocardial Oxygen Consumption In Healthy Exercising Humans

Abstract Aim: This study investigated the changes in brain blood flow velocity, arterial oxygen saturation and myocardial oxygen consumption in healthy exercising humans. The specific objectives were to determine the blood flow velocities in the middle cerebral artery (MCA), anterior cerebral artery (ACA), and internal carotid artery (ICA), as well as assess blood pressure parameters, heart rate, arterial oxygen saturation, rate pressure product, and myocardial oxygen saturation. Methods: Sixteen healthy individuals (age range: 18-30 years) were recruited for the study. The participants underwent stepping stool exercise, which involved a standardized protocol of stepping up and down a stool for a specified duration. Transcranial Doppler ultrasound was utilized as the primary tool to measure blood flow velocities across the cerebral arteries. Additionally, blood pressure, heart rate, arterial oxygen saturation, rate pressure product, and myocardial oxygen saturation were monitored throughout the exercise session. Results: Following the stepping stool exercise, significant increases were observed in the blood flow velocities of the MCA (p < 0.05), indicating improved cerebral perfusion in this specific artery. Arterial blood pressure, heart rate, rate pressure product and myocardial oxygen consumption also increased (p < 0.05). However, no significant changes were noted in the blood flow velocities of the ICA (p ˃ 0.05), ACA (p ˃ 0.05) as well as the arterial oxygen saturation Conclusion: The observed increase in MCA blood velocity suggests that exercise may have a beneficial effect on cerebral hemodynamics. Also, the increases in blood pressure, heart rate, rate pressure product and myocardial oxygen consumption, indicate an increased workload on the cardiovascular system during exercise. However, the non-significant changes observed in the velocities of the ICA or ACA suggest that the response to exercise may vary among different cerebral arteries and the non-significant change in arterial oxygen consumption indicates the reduced capacity of hemoglobin for carrying oxygen. Overall, these findings contribute to our understanding of the complex relationship between exercise, cerebral blood flow, and cardiovascular parameters.