Objective: A mathematic model may describe change in bloodflow through arteria femoralis from rest to exercise. To understand the complexity of the hemodynamic change at the onset of exercise this may be helpful and illuminate some of the most important regulating mechanisms .The aim of this study was to test and improve such an existing mathematical model.Methods:This mathematic model consist of the baroreflex, a heart, a linear elastic arterial reservoir and two parallel restrictive vascular beds representing exercising and non exercising muscles. Mean arterial pressure, heart rate, stroke volume and blodflow through the femoral artery on site was measured in ten healthy volunteers. The measured data were compared to the data calculated in the mathematical model using optimizing algorithms minimizing error.Results and conclusion:The calculations in our mathematic model fit well with the measured values in healthy volunteers. This indicate that we have isolated and implemented the most important factors in our model for calculation of changes in bloodflow during onset of exercise.