Cardiorespiratory and perceptual responses to self-regulated and imposed submaximal arm–leg ergometry

This study compared cardiorespiratory and perceptual responses to exercise using self-regulated and imposed power outputs distributed between the arms and legs.

Ten males (age 21.7 ± 3.4 years) initially undertook incremental arm-crank ergometry (ACE) and cycle ergometry (CYC) tests to volitional exhaustion to determine peak power output (W_peak). Two subsequent tests involved 20-min combined arm–leg ergometry (ALE) trials, using imposed and self-regulated protocols, both of which aimed to elicit an exercising heart rate of 160 beats min⁻¹. During the imposed trial, arm and leg intensity were set at 40% of each ergometer-specific W_peak. During the self-regulated trial, participants were asked to self-regulate cadence and resistance to achieve the target heart rate. Heart rate (HR), oxygen uptake (\(\dot {V}{{\text{O}}_{\text{2}}}\)), pulmonary ventilation (\({\dot {V}_{\text{E}}}\)), and ratings of perceived exertion (RPE) were recorded continuously.

As expected, there were no differences between imposed and self-regulated trials for HR, \(\dot {V}{{\text{O}}_{\text{2}}}\)_, and \({\dot {V}_{\text{E}}}\) (all P ≥ 0.05). However, central RPE and local RPE for the arms were lower during self-regulated compared imposed trials (P ≤ 0.05). Lower RPE during the self-regulated trial was related to preferential adjustments in how the arms (33 ± 5% W_peak) and legs (46 ± 5% W_peak) contributed to the exercise intensity.

This study demonstrates that despite similar metabolic and cardiovascular strain elicited by imposed and self-regulated ALE, the latter was perceived to be less strenuous, which is related to participants doing more work with the legs and less work with the arms to achieve the target intensity.