| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, 94720; 2 University of Colorado Health Sciences Center, Division of Cardiology, Denver, Colorado 80262; and 3 Geriatric Research, Education, and Clinical Center, Palo Alto Veterans Affairs Health Care System, Palo Alto, California 95304
The hypothesis that
endurance training increases gluconeogenesis (GNG) during rest and
exercise was evaluated. We determined glucose turnover with
[6,6-2H]glucose and lactate incorporation into
glucose by use of [3-13C]lactate during 1 h of
cycle ergometry at two intensities [45 and 65% peak
O2 consumption
(
O2 peak)]
before and after training [65% pretraining
O2 peak],
same absolute workload (ABT), and 65% posttraining
O2 peak, same
relative intensity (RLT). Nine males (178.1 ± 2.5 cm, 81.8 ± 3.3 kg, 27.4 ± 2.0 yr) trained for 9 wk on a cycle ergometer 5 times/wk for 1 h at 75%
O2 peak. The power
output that elicited 66.0 ± 1.1% of
O2 peak pretraining elicited 54.0 ± 1.7% posttraining. Rest and exercise arterial glucose concentrations were similar before and after training, regardless of exercise intensity. Arterial lactate concentration during
exercise was significantly greater than at rest before and after
training. Compared with 65% pretraining, arterial lactate concentration decreased at ABT (4.75 ± 0.4 mM, 65% pretraining; 2.78 ± 0.3 mM, ABT) and RLT (3.76 ± 0.46 mM) (P < 0.05). At
rest after training, the percentage of glucose rate of appearance
(Ra) from GNG more than doubled (1.98 ± 0.5%
pretraining; 5.45 ± 1.3% posttraining), as did the rate of GNG (0.11 ± 0.03 mg · kg
1 · min1
pretraining, 0.24 ± 0.06 mg · kg1 · min1
posttraining). During exercise after training, %glucose Ra
from GNG increased significantly at ABT (2.3 ± 0.8% at 65% pre- vs. 7.6 ± 2.1% posttraining) and RLT (6.1 ± 1.5%), whereas GNG
increased almost threefold (P < 0.05) at ABT (0.24 ± 0.08 mg · kg1 · min1
65% pre-, and 0.71 ± 0.18 mg · kg1 · min1
posttraining) and RLT (0.75 ± 0.26 mg · kg1 · min1). We conclude that endurance
training increases gluconeogenesis twofold at rest and threefold during
exercise at given absolute and relative exercise intensities.
exertion; lactate; glucose; stable isotopes
This article has been cited by other articles:
|
|
 |
|
  H. B. Nielsen, M. A. Febbraio, P. Ott, P. Krustrup, and N. H. Secher Hepatic lactate uptake versus leg lactate output during exercise in humans J Appl Physiol, October 1, 2007; 103(4): 1227 - 1233. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. C. Hannukainen, P. Nuutila, B. Ronald, J. Kaprio, U. M. Kujala, T. Janatuinen, O. J. Heinonen, J. Kapanen, T. Viljanen, M. Haaparanta, et al. Increased physical activity decreases hepatic free fatty acid uptake: a study in human monozygotic twins J. Physiol., January 1, 2007; 578(1): 347 - 358. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. C. Hannukainen, P. Nuutila, J. Kaprio, O. J Heinonen, U. M. Kujala, T. Janatuinen, T. Ronnemaa, J. Kapanen, M. Haaparanta-Solin, T. Viljanen, et al. Relationship between local perfusion and FFA uptake in human skeletal muscle--no effect of increased physical activity and aerobic fitness J Appl Physiol, November 1, 2006; 101(5): 1303 - 1311. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J.-s. Kim, K. W. Hinchcliff, M. Yamaguchi, L. A. Beard, C. D. Markert, and S. T. Devor Exercise training increases oxidative capacity and attenuates exercise-induced ultrastructural damage in skeletal muscle of aged horses J Appl Physiol, January 1, 2005; 98(1): 334 - 342. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Thomas, P. Sirvent, S. Perrey, E. Raynaud, and J. Mercier Relationships between maximal muscle oxidative capacity and blood lactate removal after supramaximal exercise and fatigue indexes in humans J Appl Physiol, December 1, 2004; 97(6): 2132 - 2138. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. C. Henderson, M. A. Horning, S. L. Lehman, E. E. Wolfel, B. C. Bergman, and G. A. Brooks Pyruvate shuttling during rest and exercise before and after endurance training in men J Appl Physiol, July 1, 2004; 97(1): 317 - 325. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. Roef, K. de Meer, S. C. Kalhan, H. Straver, R. Berger, and D.-J. Reijngoud Gluconeogenesis in humans with induced hyperlactatemia during low-intensity exercise Am J Physiol Endocrinol Metab, June 1, 2003; 284(6): E1162 - E1171. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. F. Miller, J. A. Fattor, K. A. Jacobs, M. A. Horning, S.-H. Suh, F. Navazio, and G. A. Brooks Metabolic and cardiorespiratory responses to "the lactate clamp" Am J Physiol Endocrinol Metab, November 1, 2002; 283(5): E889 - E898. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. K. Trimmer, J.-M. Schwarz, G. A. Casazza, M. A. Horning, N. Rodriguez, and G. A. Brooks Measurement of gluconeogenesis in exercising men by mass isotopomer distribution analysis J Appl Physiol, July 1, 2002; 93(1): 233 - 241. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. B. Nielsen, J. O. Clemmesen, C. Skak, P. Ott, and N. H. Secher Attenuated hepatosplanchnic uptake of lactate during intense exercise in humans J Appl Physiol, April 1, 2002; 92(4): 1677 - 1683. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Podolin, B. K. Wills, I. O. Wood, M. Lopez, R. S. Mazzeo, and D. A. Roth Attenuation of age-related declines in glucagon-mediated signal transduction in rat liver by exercise training Am J Physiol Endocrinol Metab, September 1, 2001; 281(3): E516 - E523. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. K. Trimmer, G. A. Casazza, M. A. Horning, and G. A. Brooks Autoregulation of glucose production in men with a glycerol load during rest and exercise Am J Physiol Endocrinol Metab, April 1, 2001; 280(4): E657 - E668. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
