Influence of perceived caffeine ingestion upon submaximal exercise to exhaustion

[摘要] Each Ss performed the two submaximal tests to exhaustion after taking an artificially sweetened lemonade beverage labeled ;;caffeine;; previous to one test and a beverage labeled ;;noncaffeine;; previous to the other test. The order of the tests was randomly chosen. Respiratory gases were analysed and heart rates were monitored for cross-country runners (n=l3) from the University of Wisconsin-LaCrosse, who ran 40-60 mi/wk, while each performed a V02 max test and two submaximal tests on a treadmill. The workload at which the subjects ran during the submaximal tests was determined by the grade and speed at which they reached , approximately 85% of their V0 2 max during the initial max test. A dependent t-test performed on the times to exhaustion, RPE;;s at minutes 2 and 12, heart rates, and RER;;s between the caffeine and noncaffeine trials revealed no significant differences (p < .05; t > 1.356) for any of these parameters. The results indicated that the belief that the subjects had taken a significant amount of caffeine did not produce a significant change in endurance performance.

[发布机构] University of Wisconsin

[关键词] Caffeine -- Psychological aspects