Single‐vs. double‐leg cycling: lower cardiorespiratory demands and perceived effort for a greater relative power output

Abstract

Single‐leg cycling is an insightful model of unilateral exercise. It affords a unique comparison of exercise interventions in a within‐subject manner, as the addition of a counterweight to the contralateral pedal facilitates the ‘feel’ of normal double‐leg cycling. The present study characterized physiological responses to single‐ and double‐leg cycling performed at the same relative intensities in twelve men (age: 21 ± 2 years; BMI: 24 ± 3 kg/m2). Graded‐exercise tests initially established that peak oxygen uptake (VO2 peak; +31%), ventilation (VE peak; +33%), heart rate (HRpeak; +9%), and power output (PPO; +78%) were higher (main effect of mode; p < 0.05) during double‐compared to single‐leg cycling. On separate days, subjects subsequently performed four experimental trials, which involved 30‐min bouts of either moderate‐intensity continuous training (MICT) or high‐intensity interval training (HIIT) in a single‐ or double‐leg manner. Although performed at the same percentage of the respective PPO, single‐leg exercise elicited a greater average power output per leg than double‐leg exercise (+13%; p < 0.001). In contrast, average EMG responses from the vastus lateralis and vastus medialis were similar for single‐ and double‐leg cycling (p > 0.05), although the semitendinosus was activated to a greater extent for single‐leg cycling relative to double‐leg cycling (p < 0.001). Single‐leg cycling elicited markedly lower VE, VO2, and HR responses and ratings of perceived exertion compared to double‐leg cycling (p < 0.05). In summary, single‐leg cycling allows for a greater power output (per leg) than double‐leg cycling, while eliciting lower cardiorespiratory and perceptual responses.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada (NSERC)