Biomaterial Database

Exogenous glucose oxidation during exercise in endurance-trained and untrained subjects. 1997

A E Jeukendrup, and M Mensink, and W H Saris, and A J Wagenmakers

Department of Human Biology, Maastricht University, The Netherlands. A.Jeukendrup@HB.UNIMAAS.NL

To investigate the effect of training status on the fuel mixture used during exercise with glucose ingestion, seven endurance-trained cyclists (Tr; maximum O2 uptake 67 +/- 2.3 ml.kg-1.min-1) and eight untrained subjects (UTr; 48 +/- 2 ml.kg-1.min-1) were studied during 120 min of exercise at approximately 60% maximum O2 uptake. At the onset of exercise, 8 ml.kg-1.min-1 of an 8% naturally enriched [13C]glucose solution was ingested and 2 ml/kg every 15 min thereafter. Energy expenditure was higher in Tr subjects compared with UTr subjects (3,404 vs. 2,630 kJ; P < 0.01). During the second hour, fat oxidation was higher in Tr subjects (37 +/- 2 g) compared with UTr subjects (23 +/- 1 g), whereas carbohydrate oxidation was similar (116 +/- 8 g in Tr subjects vs. 114 +/- 4 g in UTr subjects). No differences were observed in exogenous glucose oxidation (50 +/- 2 g in Tr subjects and 45 +/- 3 g in UTr subjects, respectively). Peak exogenous glucose oxidation rates were similar in the two groups (0.95 +/- 0.07 g/min in Tr subjects and 0.96 +/- 0.03 g/min in UTr subjects). It is concluded that the higher energy expenditure in Tr subjects during exercise at the same relative exercise intensity is entirely met by a higher rate of fat oxidation without changes in the rates of exogenous and endogenous carbohydrates.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D005260	Female		Females
D005947	Glucose	A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.	Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D015444	Exercise	Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.	Aerobic Exercise,Exercise, Aerobic,Exercise, Isometric,Exercise, Physical,Isometric Exercise,Physical Activity,Acute Exercise,Exercise Training,Activities, Physical,Activity, Physical,Acute Exercises,Aerobic Exercises,Exercise Trainings,Exercise, Acute,Exercises,Exercises, Acute,Exercises, Aerobic,Exercises, Isometric,Exercises, Physical,Isometric Exercises,Physical Activities,Physical Exercise,Physical Exercises,Training, Exercise,Trainings, Exercise