Regulation of human respiration during a combination of resistive loading and muscular activity

: In 9 healthy subjects, effects of additional non-elastic resistance (the resistive load) on parameters of the respiration control were shown to be slight in resting whereas in muscular activity they involved a rearrangement of the respiration pattern and a considerable increase of inspiratory and expiratory activities. As opposed to these adaptive responses, however, the resistive load, the inspiratory-expiratory one in particular, reduced the increment of lung ventilation associated with the load, and led to a hypercapnia. Physiological mechanisms of these shifts are discussed.