title: The effect of pedaling cadence and power output on mechanomyographic amplitude and mean power frequency during submaximal cycle ergometry.
abstract: The purpose of this study was to examine the effects of power output and pedaling cadence on the amplitude and mean power frequency (MPF) of the mechanomyographic (MMG) signal during submaximal cycle ergometry. Nine adults (mean age +/- SD = 22.7 +/- 2.1 yrs) performed an incremental (25 W increase every min) test to exhaustion on an electronically braked cycle ergometer to determine VO2Peak and Wpeak. The subjects also performed three, 8 min continuous, constant power output rides (randomly ordered) at 35%, 50%, and 65% Wpeak. The continuous 8 min workbouts were divided into 4 min epochs. The subjects pedaled at either 50 or 70 rev x min(-1) (randomized) during the first 4 min epoch, then changed to the alternate cadence during the second 4 min epoch. The MMG signal was recorded from the vastus lateralis during the final 10 s of each minute. Two separate two-way [cadence (50 and 70 rev x min(-1)) x %Wpeak (35, 50, and 65)] repeated measures ANOVAs indicated that MMG amplitude followed power output, but not pedaling cadence, whereas MMG MPF was not consistently affected by power output or pedaling cadence. Furthermore, these findings suggested that power output was modulated by motor unit recruitment and not rate coding.
authors.affiliation: Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, Nebraska 68583-0806, USA. rhendri7@unlserve.unl.edu
authors.forename: C R
authors.initials: CR
authors.lastname: Hendrix
authors.forename: A J
authors.initials: AJ
authors.lastname: Bull
authors.forename: T J
authors.initials: TJ
authors.lastname: Housh
authors.forename: S R
authors.initials: SR
authors.lastname: Rana
authors.forename: J T
authors.initials: JT
authors.lastname: Cramer
authors.forename: T W
authors.initials: TW
authors.lastname: Beck
authors.forename: J P
authors.initials: JP
authors.lastname: Weir
authors.forename: M H
authors.initials: MH
authors.lastname: Malek
authors.forename: M
authors.initials: M
authors.lastname: Mielke