title: Limb movement frequency is a significant modulator of the ventilatory response during submaximal cycling exercise in humans.
abstract: Human experimentation investigating the contribution of limb movement frequency in determining the fast exercise drive to breathe has produced controversial findings. To evaluate the role of limb movement frequency in determining the fast exercise drive to breathe, endurance runners and recreationally-active controls performed two sinusoidal exercise protocols on a cycle ergometer. One protocol was performed at constant workload with sinusoidal pedaling cadence, and a second with sinusoidal workload at constant cadence. Metabolic rate (VO2) increases and means were matched between these two experiments. The ventilatory response was significantly faster when limb movement speed was varied, compared to when pedal loading was varied (18.49 ± 15.6s vs. 50.5 ± 14.5s, p<0.05). Ventilation response amplitudes were significantly higher during pedal cadence variation versus pedal loading variation (3.99 ± 0.25 vs. 2.58 ± 0.17 L/min, p<0.05). Similar findings were obtained for endurance athletes, with significantly attenuated ventilation responses to exercise versus control subjects. We conclude that fast changes in limb movement frequency are a potent stimulus for ventilation at submaximal workloads, and that this response is susceptible to attenuation through training.
authors.affiliation: Graduate Department of Exercise Sciences, University of Toronto, 100 Devonshire Place, Toronto, Ontario M5S 2C9, Canada; Physiology and Experimental Medicine, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Caterini
authors.affiliation: Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada; Department of Anaesthesia, University of Toronto Health Network, 200 Elizabeth St., Toronto, Ontario M5G 2C4 Canada.
authors.forename: James
authors.initials: J
authors.lastname: Duffin
authors.affiliation: Physiology and Experimental Medicine, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada; Faculty of Kinesiology and Physical Education, University of Toronto, 100 Devonshire Place, Toronto, Ontario M5S2C9, Canada. Electronic address: greg.wells@utoronto.ca.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Wells
mesh_terms: D000328:Adult; D056352:Athletes; D001642:Bicycling / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D012119:Respiration; D012420:Running / Q000502:physiology; D055815:Young Adult
keywords: Athletes; Exercise; Limb movement; Ventilation