Physiologic effects of caffeine on cross-country runners.
This study determined the physiological effects of caffeine on cross-country runners during submaximal exercise. Ten college-age subjects (5 women; 5 men) volunteered to participate in this study. After completing a VO2max test, each subject completed 2 30-minute runs at 70% VO2max on the treadmill, 1 after ingesting caffeine and the other after ingesting a placebo. A caffeine dosage of 7 mg.kg(-1) of body weight was administered. The same dosage of vitamin C was used as a placebo. The order of treatments was randomly assigned, and the trials followed a double-blind format. The physiological data were analyzed using a repeated measures analysis of variance (SPSS). Tidal volume (TV), alveolar ventilation (VA), and rating of perceived exertion (RPE) were significantly different (p < 0.05) between treatment and control groups. The results suggest that the ingestion of caffeine at 7 mg.kg(-1) of body weight prior to submaximal running might provide a modest ergogenic effect via improved respiratory efficiency and a psychological lift.
Birnbaum
Larry J
LJ
Department of Exercise Physiology, College of St. Scholastica, Duluth, Minnesota 55811, USA. lbirnbau@css.edu
Herbst
Jacob D
JD
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology*; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D012123:Pulmonary Ventilation / Q000187:drug effects; D012420:Running / Q000502:physiology*; D013990:Tidal Volume / Q000187:drug effects
D002110:Caffeine