Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

Failed excitability of spinal motoneurons induced by prolonged running exercise

Racinais, S., Girard, O., Micallef, J.P. and Perrey, S. (2007) Failed excitability of spinal motoneurons induced by prolonged running exercise. Journal of Neurophysiology, 97 (1). pp. 596-603.

Link to Published Version: https://doi.org/10.1152/jn.00903.2006
*Subscription may be required

Abstract

The main purpose of this study was to investigate the modulations in H-reflex and V-wave responses (spinal loop properties) induced by prolonged locomotion activities. The second purpose was to compare the development of central fatigue between continuous and intermittent running modes. Eleven males randomly performed two 90-min running exercises either continuously (CONT, first ventilatory threshold) or intermittently (INT, 150 s at a velocity 20% higher than that during CONT/30 s of recovery). Neuromuscular tests of the plantar flexors [including M-wave and H-reflex at rest and M-wave and V-wave during maximal voluntary contraction (MVC)] were performed before and 5 and 30 min after the running exercises. During MVC, the torque significantly decreased (P < 0.05) from preexercise to 5 and 30 min postexercise (−11 and −9%, respectively), as did the RMS/M ratio (−11 and −13%, respectively) and the V/M ratio (−19 and −37%, respectively) for the soleus muscle. At rest, the H/M ratio also decreased significantly (P < 0.001) from preexercise to 5 and 30 min postexercise (−61 and −55%, respectively). Last, no difference in the alteration of spinal loop properties was noted between CONT and INT. In conclusion, the results regarding H-reflex and V-wave suggest for the first time a modulation in spinal loop properties after prolonged running.

Item Type: Journal Article
Publisher: American Physiological Society
Copyright: © 2007 by the American Physiological Society
URI: http://researchrepository.murdoch.edu.au/id/eprint/45958
Item Control Page Item Control Page