Cardiorespiratory and subjective responses to incremental and constant load ergometry with arms and legs

Aerobic exercises in which both arm and legs are used are becoming more popular for conditioning and rehabilitation. In order to clarify our understanding of physiologic and subjective responses to work of this type, two experiments were conducted using legs and/or arms. In the first, incremental cycle ergometry was done with the arms (A), legs (L), and combined, in which either 10% (A-10) or 25% (A-25) of the power output (PO) was done by the arms. Peak rate of oxygen consumption (VO2) and heart rate (HR) were significantly lower for A, but the other three conditions did not differ significantly. Ventilatory breakpoint (VB) was significantly higher for A-10 than for L. The second study used 60 minutes of constant-load work at a PO of approximately 115% of the PO at which the VB occurred in the L incremental test, to stimulate an aerobic training session. During the 60 minutes, VO2 and cardiac output were significantly higher, and systolic blood pressure (SBP) significantly lower for A-25 than for L, with A-10 values generally failing between the two. The HR-SBP products and ratings of perceived exertion were quite similar for the three modes. Thus, assigning some of the PO to the arms allowed a greater metabolic load to be maintained with no greater cardiovascular or subjective strain, suggesting that this type of exercise might be valuable for aerobic conditioning, cardiorespiratory rehabilitation, and weight control.