Intercept Shift in the Breathlessness/ Ventilation Relationship in Response to Progressive Increase in Workload

The relationship between breathlessness based on the visual analog scale (VAS) and expired pulmonary ventilation (VE) has been investigated under different experimental conditions. The `Newcastle effect’ revealed for the first time that a repetitive exercise protocol over a period of ten days increased the intercept without change in the slope of VASNE relationship1. Whether experiments were conducted daily or weekly, the time course of the intercept plateaued after around 5 to 6 weeks of exercise training2. A similar effect has been shown to occur during volitional tracking of an inspiratory resistive breathing pattern2.