Inter-individual variability in the patterns of responses for electromyography and mechanomyography during cycle ergometry using an RPE-clamp model.
OBJECTIVE
To examine inter-individual variability versus composite models for the patterns of responses for electromyography (EMG) and mechanomyography (MMG) versus time relationships during moderate and heavy cycle ergometry using a rating of perceived exertion (RPE) clamp model.


METHODS
EMG amplitude (amplitude root-mean-square, RMS), EMG mean power frequency (MPF), MMG-RMS, and MMG-MPF were collected during two, 60-min rides at a moderate (RPE at the gas exchange threshold; RPEGET) and heavy (RPE at 15 % above the GET; RPEGET+15 %) intensity when RPE was held constant (clamped). Composite (mean) and individual responses for EMG and MMG parameters were compared during each 60-min ride.


RESULTS
There was great inter-individual variability for each EMG and MMG parameters at RPEGET and RPEGET+15 %. Composite models showed decreases in EMG-RMS (r (2) = -0.92 and R (2) = 0.96), increases in EMG-MPF (R (2) = 0.90), increases in MMG-RMS (r (2) = 0.81 and 0.55), and either no change or a decrease (r (2) = 0.34) in MMG-MPF at RPEGET and RPEGET+15 %, respectively.


CONCLUSIONS
The results of the present study indicated that there were differences between composite and individual patterns of responses for EMG and MMG parameters during moderate and heavy cycle ergometry at a constant RPE. Thus, composite models did not represent the unique muscle activation strategies exhibited by individual responses when cycling in the moderate and heavy intensity domains when using an RPE-clamp model.
Department of Nutrition and Health Sciences, 110 Ruth Leverton Hall, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA. kcochrane@unl.edu.
Kristen C
KC
Cochrane-Snyman
Department of Nutrition and Health Sciences, 110 Ruth Leverton Hall, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
Terry J
TJ
Housh
Department of Nutrition and Health Sciences, 110 Ruth Leverton Hall, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
Cory M
CM
Smith
Department of Nutrition and Health Sciences, 110 Ruth Leverton Hall, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
Ethan C
EC
Hill
Department of Nutrition and Health Sciences, 110 Ruth Leverton Hall, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
Nathaniel D M
ND
Jenkins
Department of Nutrition and Health Sciences, 110 Ruth Leverton Hall, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
Richard J
RJ
Schmidt
Department of Nutrition and Health Sciences, 110 Ruth Leverton Hall, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
Glen O
GO
Johnson
D003198:Computer Simulation; D004576:Electromyography / Q000379:methods*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D009213:Myography / Q000379:methods*; D010465:Perception / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
Cycle ergometry; Electromyography; Mechanomyography; RPE