Effects of caffeine ingestion on thermoregulatory and myocardial function during endurance performance.
The effect of caffeine administration on thermoregulatory and myocardial function during endurance performance was studied. A caffeine solution (250 ml; 5 mg caffeine/kg body weight) ingested 1 hour prior to 2 hours of running by 5 subjects was shown to have no significant effect on sweat loss, water deficit, percentage change in plasma volume, final rectal temperature and serum electrolyte levels, as compared with a similar control group who were given a caffeine-free drink. The rectal temperatures in both groups did, however, reach levels known to be associated with heatstroke despite a recommended regimen of fluid replacement. No pathological electrocardiographic changes occurred in either group. It is therefore concluded that the use of caffeine for ergogenic purposes by young athletes is a relatively safe procedure.
D000293:Adolescent; D000328:Adult; D001831:Body Temperature / Q000187:drug effects; D001833:Body Temperature Regulation / Q000187:drug effects*; D001834:Body Water / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D005082:Physical Exertion / Q000187:drug effects*; D010953:Plasma Volume / Q000187:drug effects; D013542:Sweat / Q000378:metabolism
D002110:Caffeine