Effects of Added Breathing Resistance on Respiratory Pattern during Mild and Moderate Exercises

In six healthy male subjects, the changes of respiratory airflow rate and heart rate were de-termined in sensory units of five just noticeable difference (JND) steps caused by inspiratory resistive (IR) loads ranging 0.28-1. 62 kPa.Ls and physical stimuli in IR corresponding to JND steps andcombined resistance (CR) of different ratios equivalent to 2, 4 JND sensation at rest and duringmild and moderate muscular exercises (250 and 500 kgm·min) performed on a bicycle ergometer.The results suggest that the tendency of effects on respiratory pattern, within the test range of IRloads, are approximately consistent at rest and during mild and moderate exercise, that when theCR load is carried, the changes of respiratory pattern at rest and during mild exercise are similar,but more apparently during moderate exercise, and that the heart rote only increases with the rise ofexertion intensity, without apparent influence of resistive loads.