Metabolic and circulatory responses to the ingestion of glucose polymer and glucose/electrolyte solutions during exercise in man.
Six men exercised on a cycle ergometer for 60 min on two occasions one week apart, at 68 +/- 3% of VO2max. On one occasion, a dilute glucose/electrolyte solution (E: osmolality 310 mosmol X kg-1, glucose content 200 mmol X l-1) was given orally at a rate of 100 ml every 10 min, beginning immediately prior to exercise. On the other occasion, a glucose polymer solution (P: osmolality 630 mosmol X kg-1, glucose content equivalent to 916 mmol X l-1) was given at the same rate. Blood samples were obtained from a superficial forearm vein immediately prior to exercise and at 15-min intervals during exercise; further samples were obtained at 15-min intervals for 60 min at rest following exercise. Heart rate and rectal temperature were measured at 5-min intervals during exercise. Blood glucose concentration was not different between the two tests during exercise, but rose to a peak of 8.7 +/- 1.2 mmol X l-1 (mean +/- SD) at 30-min post-exercise when P was drunk. Blood glucose remained unchanged during and after exercise when E was drunk. Plasma insulin levels were unchanged during exercise and were the same on both trials, but again a sharp rise in plasma insulin concentration was seen after exercise when P was drunk. The rate of carbohydrate oxidation during exercise, as calculated from VO2 and the respiratory exchange ratio, was not different between the two tests.(ABSTRACT TRUNCATED AT 250 WORDS)
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D004573:Electrolytes / Q000494:pharmacology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005947:Glucose / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007328:Insulin / Q000097:blood; D007773:Lactates / Q000097:blood; D008297:Male; D008660:Metabolism / Q000187:drug effects*; D009994:Osmolar Concentration; D010101:Oxygen Consumption / Q000187:drug effects; D005082:Physical Exertion; D010953:Plasma Volume / Q000187:drug effects; D011108:Polymers / Q000494:pharmacology*
D001786:Blood Glucose; D004573:Electrolytes; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D007773:Lactates; D011108:Polymers; D005947:Glucose