title: Factors affecting the increased energy expenditure during passive cycling.
abstract: Short-duration passive cycling, during which a motor drives the pedals, elevates metabolic energy expenditure. Our purpose was to investigate the feasibility of passive cycling as a physical inactivity countermeasure by quantifying how the number of legs involved, cycling cadence, and habituation influence energy expenditure. Eleven non-cyclists participated. We compared one- and two-leg passive cycling at cadences of 60 and 90 RPM. To investigate if there are habituation effects, we conducted multiple 5-min trials and a prolonged 30-min passive cycling trial. The increase in energy expenditure above rest during passive cycling was significantly greater for two legs compared to one leg (39 vs. 16% at 60 RPM and 96 vs. 45% at 90 RPM). The increase in energy expenditure above rest was greater for 90 versus 60 RPM two-leg passive cycling (96 vs. 39%; p < 0.001). Repeated trials showed no evidence of habituation and the increase in energy expenditure was maintained for the duration of the 30-min trial. In conclusion, energy expenditure during passive cycling is directly related to the number of legs involved and cycling cadence. Two-leg passive cycling at 90 RPM resulted in energy expenditures similar to the walking workstation, suggesting its potential as a physical inactivity countermeasure.
authors.affiliation: Department of Integrative Physiology, UCB 354, University of Colorado, Boulder, CO 80309, USA. James.Peterman@colorado.edu
authors.forename: James E
authors.initials: JE
authors.lastname: Peterman
authors.forename: Rodger
authors.initials: R
authors.lastname: Kram
authors.forename: William C
authors.initials: WC
authors.lastname: Byrnes
mesh_terms: D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007899:Leisure Activities; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D012307:Risk Factors; D015854:Up-Regulation / Q000502:physiology; D055815:Young Adult