External power output changes during prolonged cycling with electrical stimulation

Author： Theisen D. Fornusek C. Raymond J. Davis G. M.

ISSN： 1650-1977

Source： Journal of Rehabilitation Medicine, Vol.34, Iss.4, 2002-07, pp. : 171-175

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

This study analysed external power output and physiologic responses in 5 individuals with paraplegia during 40 minutes of electrical stimulation leg cycle exercise. Cycling was performed on a motor-driven isokinetic ergometer that enabled precise determinations of power output. Electrical stimulation was increased to 120–140 mA within the first 5 minutes and remained constant thereafter. Power output increased to 10.7 ± 3.0 W after 2 minutes, dropped to 5.3 ± 1.8 W after 6 minutes and subsequently recovered to 8.2 ± 2.2 and 6.1 ± 2.3 W after 19.5 and 40 minutes, respectively. Oxygen consumption increased to 0.47 ± 0.09 l/min after 6 minutes and declined during the second half of the exercise bout. Gross mechanical efficiency after 19.5 minutes was elevated compared with the value after 6 minutes. Heart rate was significantly increased at the end of the trial. The time-dependent variability of power output and physiological responses question the concept of steady state for this form of exercise.