Effects of an Ad Libitum, High Carbohydrate Diet and Aerobic Exercise Training on Insulin Action and Muscle Metabolism in Older Men and Women
Autor: | William J. Evans, James D. Fluckey, Rick H. Williams, Raymond D. Starling, Robert H. Coker, Dennis H. Sullivan, Nicholas P. Hays |
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Rok vydání: | 2006 |
Předmět: |
Male
Aging medicine.medical_specialty medicine.medical_treatment Body Mass Index Impaired glucose tolerance chemistry.chemical_compound Oxygen Consumption Weight loss Internal medicine Weight Loss Dietary Carbohydrates medicine Humans Insulin Aerobic exercise Obesity Exercise physiology Muscle Skeletal Exercise Aged Aged 80 and over Analysis of Variance Glycogen business.industry Body Weight Middle Aged medicine.disease Treatment Outcome Endocrinology chemistry Body Composition Body Constitution Female Analysis of variance Geriatrics and Gerontology medicine.symptom Energy Intake business Body mass index |
Zdroj: | The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 61:299-304 |
ISSN: | 1758-535X 1079-5006 |
DOI: | 10.1093/gerona/61.3.299 |
Popis: | Previous studies have demonstrated that aerobic exercise training and weight loss have independent effects on insulin-stimulated glucose disposal (ISGD). We hypothesized that ad libitum consumption of a high-carbohydrate diet would result in weight loss and improved ISGD, and that aerobic exercise training would facilitate greater improvements in ISGD compared with diet alone.Older participants (13 women, 9 men; age = 66 +/- 1 year) with impaired glucose tolerance were randomly assigned to an ad libitum diet alone (18% fat, 19% protein, 63% carbohydrate) or this diet plus aerobic exercise training (4 d/wk, 45 min/d, 80% VO(2peak)) for 12 weeks. ISGD, abdominal fat distribution, muscle glycogen, and glycogen synthase activity were assessed pre- and postintervention.Consumption of the diet resulted in significant weight loss and an improvement in ISGD. Consumption of the diet plus exercise training also resulted in weight loss and increased ISGD, but results were not significantly different from those in the diet-alone group. Mean abdominal visceral and subcutaneous adipose tissue cross-sectional areas were smaller postintervention compared to baseline with no difference between groups. Exercise training and consumption of the diet increased muscle glycogen content (344.7 +/- 21.3 to 616.7 +/- 34.4 micromol.g(-1)) and decreased glycogen synthase activity (0.21 +/- 0.02 to 0.13 +/- 0.01) compared to the diet alone.These results demonstrate that consumption of an ad libitum, high-carbohydrate diet alone or in combination with aerobic exercise training results in weight loss and improved insulin sensitivity. Furthermore, exercise combined with this diet appears to limit additional increases in insulin sensitivity due to muscle glycogen supercompensation with a concomitant adaptive response of glycogen synthase. |
Databáze: | OpenAIRE |
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