Influence of postexercise glucose ingestion upon serum potassium levels and ECG function.
Thirteen trained runners were studied to determine whether postexercise glucose ingestion contributes to electrocardiogram (ECG) alterations by enhancing decreases in serum potassium (K+) concentrations. For the two randomly ordered trials, subjects ingested a 100 g (25% w/v glucose polymer) drink, either alone or with the addition of 3 g of potassium chloride (KCl), within 15 min following a 90-min run. ECG parameters, serum K+, and glucose concentrations were measured preexercise (Time 0), 2-3 min post-exercise (Time 1), and 25 (Time 2) and 60 (Time 3) min postexercise. The data suggest that postexercise glucose ingestion may cause ECG changes that are not directly related to the return of K+ to muscle, and that these changes, although characteristic of hypokalemia, may be related to serum glucose excursions rather than to absolute levels of serum K+. The addition of KCl may have prevented these changes by delaying gastric emptying of glucose.
Reynolds
H C
HC
Department of Exercise and Sport Science, Colorado State University, Fort Collins 80523.
Cordain
L
L
Harris
M A
MA
Linnell
S
S
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D004562:Electrocardiography / Q000187:drug effects; D015444:Exercise / Q000502:physiology*; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D011188:Potassium / Q000097:blood*; D013177:Sports
D001786:Blood Glucose; D005947:Glucose; D011188:Potassium