PMID- 11181599
OWN - NLM
STAT- MEDLINE
DCOM- 20010510
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 90
IP  - 3
DP  - 2001 Mar
TI  - Substrate utilization during exercise with glucose and glucose plus fructose 
      ingestion in boys ages 10--14 yr.
PG  - 903-11
AB  - We measured substrate utilization during exercise performed with water (W), 
      exogenous glucose (G), and exogenous fructose plus glucose (FG) ingestion in boys 
      age 10-14 yr. Subjects (n = 12) cycled for 90 min at 55% maximal O(2) uptake 
      while ingesting either W (25 ml/kg), 6% G (1.5 g/kg), or 3% F plus 3% G (1.5 
      g/kg). Fat oxidation increased during exercise in all trials but was higher in 
      the W (0.28 +/- 0.023 g/min) than in the G (0.24 +/- 0.023 g/min) and FG (0.25 
      +/- 0.029 g/min) trials (P = 0.04). Conversely, total carbohydrate (CHO) 
      oxidation decreased in all trials and was lower in the W (0.63 +/- 0.05 g/min) 
      than in the G (0.78 +/- 0.051 g/min) and FG (0.74 +/- 0.056 g/min) trials (P = 
      0.009). Exogenous CHO oxidation, as determined by expired (13)CO(2), reached a 
      maximum of 0.36 +/- 0.032 and 0.31 +/- 0.030 g/min at 90 min in G and FG, 
      respectively (P = 0.04). Plasma insulin levels decrease during exercise in all 
      trials but were twofold higher in G than in W and FG (P < 0.001). Plasma glucose 
      levels decreased transiently after the onset of exercise in all trials and then 
      returned to preexercise values in the W and FG (approximately 4.5 mmol/l) trials 
      but were elevated by approximately 1.0 mmol/l in the G trial (P < 0.001). Plasma 
      lactate concentrations decreased after the onset of exercise in all trials but 
      were lower by approximately 0.5 mmol/l in W than in G and FG (P = 0.02). Thus, in 
      boys exercising at a moderate intensity, the oxidation rate of G plus F is 
      slightly less than G alone, but both spare endogenous CHO and fat to a similar 
      extent. In addition, compared with flavored W, the ingestion of G alone and of G 
      plus F delays exhaustion at 90% peak power by approximately 25 and 40%, 
      respectively, after 90 min of moderate-intensity exercise.
FAU - Riddell, M C
AU  - Riddell MC
AD  - Children's Exercise and Nutrition Centre, McMaster University, Hamilton, Ontario, 
      Canada L8N 3Z5.
FAU - Bar-Or, O
AU  - Bar-Or O
FAU - Wilk, B
AU  - Wilk B
FAU - Parolin, M L
AU  - Parolin ML
FAU - Heigenhauser, G J
AU  - Heigenhauser GJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Blood Glucose)
RN  - 0 (Carbon Isotopes)
RN  - 0 (Dietary Carbohydrates)
RN  - 0 (Insulin)
RN  - 0 (Lactates)
RN  - 142M471B3J (Carbon Dioxide)
RN  - 30237-26-4 (Fructose)
RN  - IY9XDZ35W2 (Glucose)
SB  - IM
MH  - Adolescent
MH  - Blood Glucose/metabolism
MH  - Body Constitution
MH  - Carbohydrate Metabolism
MH  - Carbon Dioxide/analysis
MH  - Carbon Isotopes
MH  - Child
MH  - *Dietary Carbohydrates
MH  - Exercise/*physiology
MH  - Fructose/*metabolism
MH  - Glucose/*metabolism
MH  - Heart Rate
MH  - Humans
MH  - Insulin/blood
MH  - Lactates/blood
MH  - Least-Squares Analysis
MH  - Lipid Metabolism
MH  - Male
MH  - Oxidation-Reduction
MH  - Oxygen Consumption/*physiology
MH  - Physical Exertion/*physiology
MH  - Regression Analysis
EDAT- 2001/02/22 11:00
MHDA- 2001/05/22 10:01
CRDT- 2001/02/22 11:00
PHST- 2001/02/22 11:00 [pubmed]
PHST- 2001/05/22 10:01 [medline]
PHST- 2001/02/22 11:00 [entrez]
AID - 10.1152/jappl.2001.90.3.903 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2001 Mar;90(3):903-11. doi: 10.1152/jappl.2001.90.3.903.