title: Freely chosen cadence during a covert manipulation of ambient temperature.
abstract: The present study investigated relationships between changes in power output (PO) to torque (TOR) or freely chosen cadence (FCC) during thermal loading. Twenty participants cycled at a constant rating of perceived exertion while ambient temperature (Ta) was covertly manipulated at 20-min intervals of 20 °C, 35 °C, and 20 °C. The magnitude responses of PO, FCC and TOR were analyzed using repeated-measures ANOVA, while the temporal correlations were analyzed using Auto-Regressive Integrated Moving Averages (ARIMA). Increases in Ta caused significant thermal strain (p < .01), and subsequently, a decrease in PO and TOR magnitude (p < .01), whereas FCC remained unchanged (p = .51). ARIMA indicates that changes in PO were highly correlated to TOR (stationary r2 = .954, p = .04), while FCC was moderately correlated (stationary r2 = .717, p = .01) to PO. In conclusion, changes in PO are caused by a modulation in TOR, whereas FCC remains unchanged and therefore, unaffected by thermal stressors.
authors.affiliation: Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, Ontario, Canada.
authors.forename: Geoffrey L
authors.initials: GL
authors.lastname: Hartley
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Cheung
mesh_terms: D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D013312:Stress, Physiological / Q000502:physiology*; D013696:Temperature; D019415:Torque