Caffeine withdrawal and high-intensity endurance cycling performance
In this study, we investigated the impact of a controlled 4-day caffeine withdrawal period on the effect of an acute caffeine dose on endurance exercise performance. Twelve well-trained and familiarized male cyclists, who were caffeine consumers (from coffee and a range of other sources), were recruited for the study. A double-blind placebo-controlled cross-over design was employed, involving four experimental trials. Participants abstained from dietary caffeine sources for 4 days before the trials and ingested caspulses (one in the morning and one in the afternoon) containing either placebo or caffeine (1.5 mg · kg/body weight·day). On day 5, capsules containing placebo or caffeine (3 mg/kg body weight) were ingested 90 min before completing a time trial, equivalent to one hour of cycling at 75% peak sustainable power output. Hence the study was designed to incorporate placebo-placebo, placebo-caffeine, caffeine-placebo, and caffeine-caffeine conditions. Performance time was significantly improved after acute caffeine ingestion by 1:49 ± 1:41 min (3.0%, P = 0.021) following a withdrawal period (placebo-placebo vs. placebo-caffeine), and by 2:07 ± 1:28 min (3.6%, P = 0.002) following the non-withdrawal period (caffeine-placebo vs. caffeine-caffeine). No significant difference was detetcted between the two acute caffeine trials (placebo-caffeine vs. caffeine-caffeine). Average heart rate throughout exercise was significantly higher following acute caffeine administration compared with placebo. No differences were observed in ratings of perceived exertion between trials. A 3 mg/kg dose of caffeine significantly improves exercise performance irrespective of whether a 4-day withdrawal period is imposed on habitual caffeine users.
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Aiheet: | suorituskyky kestävyys pyöräily suhde ylellinen ruoka ergogeeninen apu |
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Aihealueet: | biologiset ja lääketieteelliset tieteet kestävyys urheilu |
Tagging: | Koffein |
DOI: | 10.1080/02640414.2010.541480 |
Julkaisussa: | Journal of Sports Sciences |
Julkaistu: |
2011
|
Vuosikerta: | 29 |
Numero: | 5 |
Sivuja: | 509-515 |
Julkaisutyypit: | artikkeli |
Kieli: | englanti (kieli) |
Taso: | kehittynyt |