Performance during a 20-km cycling time-trial after caffeine ingestion

被引：20

作者：

Bortolotti, Henrique ^{[1
,2
,4
]}

Altimari, Leandro Ricardo ^{[1
,2
,3
]}

Vitor-Costa, Marcelo ^{[1
,2
]}

Cyrino, Edilson Serpeloni ^{[1
,2
,3
]}

机构：

[1] Univ Estadual Londrina, Metab Nutr & Exercise Res Grp, Londrina, Parana, Brazil

[2] Univ Estadual Londrina, Neuromuscular Syst & Exercise Res Grp, Londrina, Parana, Brazil

[3] Univ Estadual Londrina, Ctr Phys Educ & Sport, Dept Phys Educ, Londrina, Parana, Brazil

[4] Univ Sao Paulo, Sch Phys Educ & Sport, Sao Paulo, Brazil

来源：

JOURNAL OF THE INTERNATIONAL SOCIETY OF SPORTS NUTRITION | 2014年 / 11卷

关键词：

Ergogenic aid; Sports performance; Perceived exertion; Electromyography; Exercise testing; PERCEIVED EXERTION; EXERCISE; ENDURANCE; METABOLISM; MUSCLE; METAANALYSIS; WITHDRAWAL; EXHAUSTION; RESPONSES; FATIGUE;

D O I：

10.1186/s12970-014-0045-8

中图分类号：

R15 [营养卫生、食品卫生]; TS201 [基础科学];

学科分类号：

100403 ;

摘要：

Background: The objective of this study was to analyze the effect of caffeine ingestion on the performance and physiological variables associated with fatigue in 20-km cycling time trials. Methods: In a double-blind placebo-controlled crossover study, 13 male cyclists (26 +/- 10 y, 71 +/- 9 kg, 176 +/- 6 cm) were randomized into 2 groups and received caffeine (CAF) capsules (6 mg.kg(-1)) or placebo (PLA) 60 min before performing 20-km time trials. Distance, speed, power, rpm, rating of perceived exertion (RPE), electromyography (EMG) of the quadriceps muscles and heart rate (HR) were continuously measured during the tests. In addition, BRUMS questionnaire was applied before and after the tests. Results: Significant interactions were found in power and speed (P = 0.001), which were significantly higher at the end of the test (final 2 km) after CAF condition. A main effect of time (P = 0.001) was observed for RPE and HR, which increased linearly until the end of exercise in both conditions. The time taken to complete the test was similar in both conditions (PLA = 2191 +/- 158 s vs. CAF = 2181 +/- 194 s, P = 0.61). No significant differences between CAF and PLA conditions were identified for speed, power, rpm, RPE, EMG, HR, and BRUMS (P > 0.05). Conclusion: The results suggest that caffeine intake 60 min before 20-km time trials has no effect on the performance or physiological responses of cyclists.

引用

页数：7