PMID- 2180831
OWN - NLM
STAT- MEDLINE
DCOM- 19900503
LR  - 20131121
IS  - 0172-4622 (Print)
IS  - 0172-4622 (Linking)
VI  - 11
IP  - 1
DP  - 1990 Feb
TI  - Influence of carbohydrate ingestion on counterregulatory hormones during 
      prolonged exercise.
PG  - 33-6
AB  - This study was undertaken to determine the effects of ingesting 5.0 (CHO-5), 6.0 
      (CHO-6), and 7.5 g/100 ml (CHO-7.5) carbohydrate (CHO) solutions on blood glucose 
      and counterregulatory hormonal responses during prolonged intermittent exercise. 
      Eight well-trained cyclists performed four trials consisting of seven 12-min 
      cycling bouts at 70% of VO2max with 3 min rest between each ride. A final 12 min 
      ride was an all-out self-paced performance ride. During the rest interval the 
      subjects ingested either a water placebo (WP) or one of the CHO solutions at a 
      rate of 8.5 mg/kg/h (approx. 150 ml). Blood samples were taken at 0, 25, 55, 85, 
      and 115 min of exercise and were assayed for glucose, glucagon (GG), cortisol 
      (CT), insulin (IN), epinephrine (EP), and norepinephrine (NE). Blood glucose 
      levels were significantly lower in the WP trial compared to the CHO trials at 25 
      (4.6 +/- 0.2 vs 5.7 +/- 0.5 mmol/l) and 55 min (4.4 +/- 0.3 vs 5.0 +/- 0.8 
      mmol/l). At 85 min blood glucose was significantly lower in the WP compared to 
      the CHO-6 and CHO-7.5 trials. GG and IN levels were not significantly different 
      between trials; however, the GG:IN molar ratio was significantly higher in the WP 
      than in the CHO-7.5 trial. CT was significantly elevated in the WP trial compared 
      to the CHO-7.5 trial. EP and NE levels were not affected by CHO ingestion. These 
      data suggest that CHO feedings prevent the typical hormonal responses which are 
      responsible for hepatic glucose release, thus eliciting a possible hepatic 
      glycogen sparing.
FAU - Mitchell, J B
AU  - Mitchell JB
AD  - Human Performance Laboratory, Ball State University, Muncie, Indiana 47306.
FAU - Costill, D L
AU  - Costill DL
FAU - Houmard, J A
AU  - Houmard JA
FAU - Flynn, M G
AU  - Flynn MG
FAU - Fink, W J
AU  - Fink WJ
FAU - Beltz, J D
AU  - Beltz JD
LA  - eng
PT  - Clinical Trial
PT  - Controlled Clinical Trial
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Int J Sports Med
JT  - International journal of sports medicine
JID - 8008349
RN  - 0 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
RN  - 0 (Hormones)
RN  - 0 (Insulin)
RN  - 9007-92-5 (Glucagon)
RN  - WI4X0X7BPJ (Hydrocortisone)
RN  - X4W3ENH1CV (Norepinephrine)
RN  - YKH834O4BH (Epinephrine)
SB  - IM
MH  - Adult
MH  - Blood Glucose/*metabolism
MH  - Dietary Carbohydrates/*pharmacology
MH  - Epinephrine/blood
MH  - Exercise
MH  - Glucagon/blood
MH  - Hormones/*blood
MH  - Humans
MH  - Hydrocortisone/blood
MH  - Insulin/blood
MH  - Male
MH  - Norepinephrine/blood
MH  - Physical Endurance/*drug effects
EDAT- 1990/02/01 00:00
MHDA- 1990/02/01 00:01
CRDT- 1990/02/01 00:00
PHST- 1990/02/01 00:00 [pubmed]
PHST- 1990/02/01 00:01 [medline]
PHST- 1990/02/01 00:00 [entrez]
AID - 10.1055/s-2007-1024758 [doi]
PST - ppublish
SO  - Int J Sports Med. 1990 Feb;11(1):33-6. doi: 10.1055/s-2007-1024758.