Document Detail

Fuel metabolism in men and women during and after long-duration exercise.
MedLine Citation:
PMID:  9804587     Owner:  NLM     Status:  MEDLINE    
This study aimed to determine gender-based differences in fuel metabolism in response to long-duration exercise. Fuel oxidation and the metabolic response to exercise were compared in men (n = 14) and women (n = 13) during 2 h (40% of maximal O2 uptake) of cycling and 2 h of postexercise recovery. In addition, subjects completed a separate control day on which no exercise was performed. Fuel oxidation was measured using indirect calorimetry, and blood samples were drawn for the determination of circulating substrate and hormone levels. During exercise, women derived proportionally more of the total energy expended from fat oxidation (50.9 +/- 1.8 and 43. 7 +/- 2.1% for women and men, respectively, P < 0.02), whereas men derived proportionally more energy from carbohydrate oxidation (53.1 +/- 2.1 and 45.7 +/- 1.8% for men and women, respectively, P < 0.01). These gender-based differences were not observed before exercise, after exercise, or on the control day. Epinephrine (P < 0.007) and norepinephrine (P < 0.0009) levels were significantly greater during exercise in men than in women (peak epinephrine concentrations: 208 +/- 36 and 121 +/- 15 pg/ml in men and women, respectively; peak norepinephrine concentrations: 924 +/- 125 and 659 +/- 68 pg/ml in men and women, respectively). As circulating glycerol levels were not different between the two groups, this suggests that women may be more sensitive to the lipolytic action of the catecholamines. In conclusion, these data support the view that different priorities are placed on lipid and carbohydrate oxidation during exercise in men and women and that these gender-based differences extend to the catecholamine response to exercise.
T J Horton; M J Pagliassotti; K Hobbs; J O Hill
Related Documents :
2250987 - Body composition and resting energy expenditure in long term spinal cord injury.
19577377 - A "mini-fast with exercise" protocol for fat loss.
9232557 - Nutritional strategies for promoting fat utilization and delaying the onset of fatigue ...
21225277 - Physiological fitness and health adaptations from purposeful training using off-road ve...
3300497 - Exercise effects on calorie intake.
8800847 - Physiological profiles and sport specific fitness of asian elite squash players.
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  85     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1998 Nov 
Date Detail:
Created Date:  1998-12-29     Completed Date:  1998-12-29     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1823-32     Citation Subset:  IM    
Center for Human Nutrition, Department of Pediatrics, Universityof Colorado Health Sciences Center, Denver, Colorado 80262, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Body Weight / physiology
Energy Metabolism / physiology*
Exercise / physiology*
Gonadal Steroid Hormones / blood
Hormones / blood
Physical Endurance / physiology*
Physical Fitness / physiology
Pulmonary Gas Exchange / physiology
Sex Characteristics
Grant Support
Reg. No./Substance:
0/Gonadal Steroid Hormones; 0/Hormones

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Effects of aging on cardiac output, regional blood flow, and body composition in Fischer-344 rats.
Next Document:  Kinetics of oxygen uptake at the onset of exercise in boys and men.