Training -induced alterations in glucose flux.
Friedlander, Anne L., Gretchen A. Casazza, Michael A. Horning, Melvin
J. Huie, George A. Brooks.
Exercise Physiology Laboratory, Departments of Human Biodynamics
and Integrative Biology, University of California, Berkeley,
California 94720
APStracts 3:0543A, 1996.
We examined the hypothesis that glucose flux was directly related to
relative exercise intensity both before and after a 10 week cycle
ergometer training program (6 d/w, 1 hr, 75% VO2peak) in 19 healthy
male subjects. Two pre-training trials (45% and 65% of VO2peak) and
two post-training trials (same absolute workload-65% of old VO2peak,
and same relative-65% of new VO2peak) were performed using a primed
-continuous infusion of [1-13C]- and [6,6-2H]glucose. Subjects were
studied post-absorptive for 90 min of rest and 1 hour of cycling
exercise. After training, subjects increased VO2peak by 9.4+/-1.5%.
Pre-training, the intensity effect on glucose kinetics was evident
between 65% and 45% of VO2peak with rate of appearance (Ra: 5.84+/
-0.23 vs. 4.73+/-0.19 mg x kg-1 x min-1), disappearance (Rd: 5.78+/
-0.19 vs. 4.73+/-0.19 mg x kg-1 x min-1), oxidation (Rox: 5.36+/-0.15
vs. 3.41+/-0.23 mg x kg-1 x min-1) and metabolic clearance (MCR:
7.03+/-0.56 vs. 5.20+/-0.28 ml x kg-1 x min-1) of glucose being
significantly greater (p
Received 3 September 1996; accepted in final form 15 November
1996.
APS Manuscript Number A845-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996