Purpose: Caffeine can be a powerful ergogenic aid for the performance of prolonged, submaximal exercise. Little evidence, however, supports an ergogenic effect of caffeine on intermittent-sprint performance. Hence, this study was conducted to examine the effects of acute caffeine ingestion on prolonged intermittent-sprint performance.
Methods: Using a double-blind, placebo-controlled design, 10 male team-sport athletes (amateur level, V̇O2peak 56.5 ± 8.0 mL·kg−1·min−1) completed two exercise trials, separated by 7 d, 60 min after ingestion of either 6 mg·kg−1 caffeine or placebo. The exercise trial was performed on a front-access cycle ergometer and consisted of 2 × 36-min halves, each composed of 18 × 4-s sprints with 2-min active recovery at 35% V̇O2peak between each sprint. Urinary caffeine levels were measured after exercise.
Results: The total amount of sprint work performed during the caffeine trial was 8.5% greater than that performed during the placebo trial in the first half (75,165.4 ± 3,902.9 vs 69,265.6 ± 3,719.7 J, P < 0.05), and was 7.6% greater in the second half (73,978.7 ± 4,092.6 vs 68,783.2 ± 3,574.4 J, P < 0.05). Similarly, the mean peak power score achieved during sprints in the caffeine trial was 7.0% greater than that achieved during the placebo trial in the first half (1330.9 ± 68.2 vs 1244.2 ± 60.7 W, P < 0.05), and was 6.6% greater in the second half (1314.5 ± 68.4 vs 1233.2 ± 59.9 W, P < 0.05). Urinary caffeine levels following the caffeine trial ranged from 3.5 to 9.1 μg·mL−1 (6.9 ± 0.6 μg·mL−1).
Conclusion: This study revealed that acute caffeine ingestion can significantly enhance performance of prolonged, intermittent-sprint ability in competitive, male, team-sport athletes.
1Laboratory, School of Human Movement and Exercise Science, The University of Western Australia, Crawley, West Australia, AUSTRALIA; and 2Clinical Pharmacology and Toxicology, Western Australian Centre for Pathology and Medical Research, Nedlands, West Australia, AUSTRALIA
Address for correspondence: Knut Thomas Schneiker, School of Human Movement and Exercise Science, The University of Western Australia, Crawley, WA 6009, Australia; E-mail: firstname.lastname@example.org.
Submitted for publication April 2005.
Accepted for publication August 2005.