The effects of a single bout of exercise on glucose
effectiveness.
Higaki, Y., T. Kagawa, J. Fujitani, A. Kiyonaga, M. Shindo, A.
Taniguchi, Y. Nakai, K. Tokuyama, M. Suzuki, and H. Tanaka.
Department of Community Health Science, Saga Medical School, Saga
849, Japan, Laboratory of Exercise Physiology, Faculty of Physical
Education, Fukuoka University, Fukuoka 814-01, Japan, Kansai-Denryoku
Hospital, Osaka 533, Japan, Division of the Science of Nursing,
College of Medical Technology, Kyoto University, Kyoto 606, Japan,
Laboratory of Biochemistry of Exercise and Nutrition, Institute of
Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki
305, Japan
APStracts 2:0472A, 1995.
The effects of a single bout of exercise on glucose effectiveness (SG)
and insulin sensitivity (SI) in twenty-two sedentary subjects was
estimated using a minimal model approach. The intravenous glucose
tolerance test (IVGTT) was performed either 1) 11 h after an exercise
bout on a cycle ergometer at the lactate threshold level (mild
exercise) for 60 min, 2) 11 h after an exercise bout at the 4mM
lactate level (hard exercise) for 36 +/- 1 min, 3) 11h after an
exhaustive exercise bout (exhaustive exercise) for 96 +/- 7 min or 4)
without any prior exercise (control). Only the exhaustive exercise
increased the glucose disappearance constant (KG) (2.69 +/- 0.28 vs.
2.05 +/- 0.13 %/min, P<0.05) and SI (15.0 +/- 2.0 vs. 10.3 +/-
0.9 x10-5 min-1pM-1, P<0.05) in comparison to the control
condition. The SG and glucose effectiveness at zero insulin (GEZI)
were not affected by any exercise conditions. However, a marked
individual difference in GEZI emerged after the exhaustive exercise
and could be divided into two subgroups: one decreased in GEZI (0.014
+/- 0.001 vs. 0.007 +/- 0.001 min-1) and the another increased in
GEZI (0.014 +/- 0.001 vs. 0.021 +/- 0.003 min-1). The former subgroup
was accompanied with elevated levels of plasma creatine kinase (CPK,
100 +/- 16 vs. 598 +/- 315 IU/L, P<0.05) and myoglobin (Mb, 46
+/- 4 vs. 126 +/- 47 ng/ml, P<0.05), while the latter subgroup
showed no significant change in CPK (99 +/- 10 vs. 128 +/- 9 IU/L,
P>0.05) and Mb (50 +/- 7 vs. 51 +/- 4 ng/ml, P>0.05). In
both subgroups, SI was similarly increased after the exhaustive
exercise. These results thus suggest that a single bout of exercise
that results in muscle damage or changes in muscle permeability, as
reflected in the increased CPK and Mb levels, decreases GEZI, while
exhaustive exercise without such alterations increases GEZI.
Received 21 April 1995; accepted in final form 24 April 1995.
APS Manuscript Number A436-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95