Lack of antioxidant adaptation to short term aerobic training in human muscle. Tiidus, Peter M., Joanne Pushkarenko, and Michael E. Houston. Department of Physical Education, Wilfrid Laurier University and Department of Kinesiology, University of Waterloo, Waterloo, ON, N2L 3C5, Canada
APStracts 3:0140R, 1996.
The effects of eight weeks of 35 min of aerobic cycle training (3 times per week) on indices of male and female human vastus lateralis muscle antioxidant status were investigated. Training resulted in significant elevations in whole body O2 max and muscle citrate synthase (CS) activity. Despite this, muscle superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities were not significantly altered by the training protocol. As well, training did not affect muscle vitamin E ([alpha]- and [delta] -tocopherol) concentrations. Glutathione status determined as the concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), total GSH (GSH + 2GSSG), and GSH/GSSG ratio was unaffected by the training protocol. There were no significant differences between males and females in any of indices of muscle antioxidant status. These results indicate that the moderate aerobic training typically performed by regularly exercising humans did not positively alter endogenous antioxidant status. This suggests that short-term aerobic training increases capacity for flux through the citric acid cycle without necessarily increasing ability to handle potential free radicals generated by the enhanced electron flux. 

Received 27 July 1995; accepted in final form 1 April 1996.
APS Manuscript Number R454-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 16 April 96