Cardiovascular and metabolic responses during functional electric stimulation cycling at different cadences.
OBJECTIVE
To determine the influence of pedaling cadence on cardiorespiratory responses and muscle oxygenation during functional electric stimulation (FES) leg cycling.


METHODS
Repeated measures.


METHODS
Laboratory.


METHODS
Nine subjects with T4 through T10 spinal cord injury (SCI) (American Spinal Injury Association grade A).


METHODS
FES cycling was performed at pedaling cadences of 15, 30, and 50 revolutions per minute (rpm).


METHODS
At each cadence, heart rate, oxygen uptake, and cardiac output were recorded during 35 minutes of cycling. Near infrared spectroscopy was used to quantify quadriceps muscle oxygenation.


RESULTS
All pedaling cadences induced similar elevations in cardiorespiratory metabolism, compared with resting values. Higher average power output was produced at 30rpm (8.2+/-0.7W, P<.05) and 50rpm (7.9+/-0.5W, P<.05) compared with 15rpm (6.3+/-0.6W). Gross mechanical efficiency was significantly higher (P<.05) at 30 and 50rpm than at 15rpm. Quadriceps muscle oxygenation did not differ with pedaling cadences.


CONCLUSIONS
Cardiorespiratory responses and muscle metabolism adjustments during FES leg cycling were independent of pedal cadence. FES cycling at a cadence of 50rpm may not confer any advantages over 30 or 15rpm for cardiovascular fitness promotion in persons with SCI.
Fornusek
Ché
C
Rehabilitation Research Centre, Discipline of Exercise and Sports Science, Faculty of Health Sciences, University of Sydney, Sydney, NSW, Australia. cfornuse@mail.usyd.edu.au
Davis
Glen M
GM
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D002320:Cardiovascular Physiological Phenomena; D004558:Electric Stimulation / Q000379:methods*; D004734:Energy Metabolism / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D018763:Muscle Fatigue / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010264:Paraplegia / Q000175:diagnosis / Q000534:rehabilitation; D005082:Physical Exertion; D011336:Probability; D012016:Reference Values; D015656:Respiratory Mechanics; D019265:Spectroscopy, Near-Infrared; D013119:Spinal Cord Injuries / Q000175:diagnosis / Q000534:rehabilitation*; D013318:Stroke Volume; D019415:Torque