PMID- 11880805
OWN - NLM
STAT- MEDLINE
DCOM- 20020416
LR  - 20220408
IS  - 0195-9131 (Print)
IS  - 0195-9131 (Linking)
VI  - 34
IP  - 3
DP  - 2002 Mar
TI  - Fuel oxidation during exercise in middle-aged men: role of training and glucose 
      disposal.
PG  - 423-9
AB  - PURPOSE: The purpose of this study was to test the hypothesis that carbohydrate 
      (CHO) utilization in middle-aged trained men is increased during hard-intensity 
      exercise and decreased during moderate-intensity exercise in comparison with 
      age-matched sedentary men. We also investigated whether a relationship between 
      CHO utilization and glucose disposal exists. METHODS: Seven trained cyclists (Tr) 
      and seven age-matched sedentary men (Sed) underwent an intravenous glucose 
      tolerance test after an overnight fast (minimal model method) to determine their 
      glucose disposal; they also performed two 1-h trials on a cycle ergometer below 
      and above their individual ventilatory threshold (VT). Substrate oxidation was 
      evaluated by indirect calorimetry. Hormonal responses were investigated during 
      exercise. RESULTS: Insulin sensitivity (SI) and glucose effectiveness (Sg) were 
      significantly higher in the Tr group than in the Sed group (P < 0.001, P < 0.03). 
      CHO oxidation was significantly higher in the Tr group than in the Sed group when 
      exercise was performed above VT, whereas CHO oxidation was higher in the Sed 
      group when exercise was performed below VT (P < 0.05). Epinephrine (Epi) response 
      during hard-intensity exercise was higher in the Tr group than in the Sed group 
      (P < 0.01). SI was negatively correlated to CHO oxidation in the Tr group (r = 
      -0.743, P < 0.05). CONCLUSION: Endurance training results in increased CHO 
      utilization during hard-intensity exercise and reduced CHO oxidation during 
      moderate-intensity exercise in middle-aged men. During hard-intensity exercise, 
      the increased CHO utilization in middle-aged trained men is associated with a 
      greater response in Epi and is inversely related with SI.
FAU - Manetta, Jerome
AU  - Manetta J
AD  - Service Central de Physiologie Clinique, Centre d'Exploration et de Readaptation 
      des Anomalies Metaboliques et Musculaires (CERAMM), CHU Lapeyronie, and 
      Laboratoire de Biochimie B, CHU Saint Eloi, 34295 Montpellier Cedex 5, France. 
      jerome.manetta@free.fr
FAU - Brun, Jean Frederic
AU  - Brun JF
FAU - Perez-Martin, Antonia
AU  - Perez-Martin A
FAU - Callis, Albert
AU  - Callis A
FAU - Prefaut, Christian
AU  - Prefaut C
FAU - Mercier, Jacques
AU  - Mercier J
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Med Sci Sports Exerc
JT  - Medicine and science in sports and exercise
JID - 8005433
RN  - 0 (Blood Glucose)
SB  - IM
MH  - Blood Glucose/*metabolism
MH  - Calorimetry, Indirect
MH  - *Carbohydrate Metabolism
MH  - *Energy Metabolism
MH  - Exercise/*physiology
MH  - Exercise Test
MH  - Glucose Tolerance Test
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - *Oxygen Consumption
MH  - Physical Endurance/*physiology
EDAT- 2002/03/07 10:00
MHDA- 2002/04/17 10:01
CRDT- 2002/03/07 10:00
PHST- 2002/03/07 10:00 [pubmed]
PHST- 2002/04/17 10:01 [medline]
PHST- 2002/03/07 10:00 [entrez]
AID - 10.1097/00005768-200203000-00007 [doi]
PST - ppublish
SO  - Med Sci Sports Exerc. 2002 Mar;34(3):423-9. doi: 
      10.1097/00005768-200203000-00007.