| Two bouts of exercise before meals, but not after meals, lower fasting blood glucose. | |
| | |
MedLine Citation:
|
PMID: 19568199 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
INTRODUCTION: Reduced counterregulatory responses to a next-day hypoglycemic challenge and hypoglycemia result from two spaced episodes of moderate-intensity exercise and have been characterized as exercise-associated autonomic failure. We hypothesized that this phenomenon is caused by postabsorptive state at the time of exercise rather than by autonomic failure. METHODS: Participants were nine healthy postmenopausal women in a crossover study. Two hours of treadmill exercise at 43% of maximal effort were performed twice a day, separated by 5 h, either 1 h before (Before-Meals trial) or 1 h after a meal (After-Meals trial). Plasma insulin, counterregulatory hormones (glucagon, growth hormone, cortisol), and metabolites (glucose, free fatty acids, ketones) were measured to evaluate the effects of nutritional timing. Analyses of HR and vagal tone were measured to assess autonomic function. RESULTS: Before-Meals exercise, but not After-Meals exercise, reduced postabsorptive plasma glucose by 20.2% during a 16-h period, without a change in counterregulatory response, and elicited postexercise ketosis. A 49% increase in insulin-glucagon ratio during meals, a 1 mM decline in glucagon glycemic threshold, and a reduced vagal tone during exercise were associated with Before-Meals but not with After-Meals trials. CONCLUSIONS: These results demonstrate that exercise performed in postabsorptive, but not in postprandial state, lowers glucoregulatory set point and glucagon glycemic threshold and is accompanied by reduced vagal tone, counterregulatory responses, and glucagon glycemic threshold and by increased insulin-glucagon ratio. Reduced counterregulatory response, altered neuroendocrine function, and sustained lowering of blood glucose are most likely the consequences of reduced carbohydrate availability during exercise. |
| | |
Authors:
|
Katarina T Borer; Elizabeth C Wuorinen; Jamie R Lukos; John W Denver; Stephen W Porges; Charles F Burant |
Related Documents
:
|
16568339 - Increase of adiponectin receptor gene expression by physical exercise in soleus muscle ... 17854409 - High volume-low intensity exercise camp and glycemic control in diabetic children. 8587489 - Metabolite and hormonal response in smokers during rest and sustained exercise. 9781319 - Hepatic glucose production during exercise. 1930919 - Effect of exercise on pharmacokinetics. 20421289 - Acute exercise reduces hepatic glucose production through inhibition of the foxo1/hnf-4... 11564979 - In-vivo intracellular ph at rest and during exercise in patients with essential hyperte... 9010689 - Mechanisms of tolerance during treatment with nitroglycerin patches for 24 h. 11676719 - The role of the diaphragm during abdominal hollowing exercises. |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural |
Journal Detail:
|
Title: Medicine and science in sports and exercise Volume: 41 ISSN: 1530-0315 ISO Abbreviation: Med Sci Sports Exerc Publication Date: 2009 Aug |
Date Detail:
|
Created Date: 2009-07-20 Completed Date: 2009-11-09 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 8005433 Medline TA: Med Sci Sports Exerc Country: United States |
Other Details:
|
Languages: eng Pagination: 1606-14 Citation Subset: IM; S |
Affiliation:
|
School of Kinesiology, University of Michigan, Ann Arbor, MI 49109-2214, USA. Katarina@umich.edu |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Blood Glucose / analysis*, metabolism Cross-Over Studies Exercise / physiology* Fasting Feeding Behavior* Female Glucagon / blood Humans Hypoglycemia / blood Ketosis / blood Middle Aged Postmenopause Time Factors |
| Grant Support | |
ID/Acronym/Agency:
|
1R15-DK066286/DK/NIDDK NIH HHS; M01-RR00042/RR/NCRR NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Blood Glucose; 9007-92-5/Glucagon |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: A mathematical model to describe fat oxidation kinetics during graded exercise.
Next Document: Exercise effects on tumorigenesis in a p53-deficient mouse model of breast cancer.