Neuromuscular responses to incremental caffeine doses: Performance and side effects
(Neuromuskuläre Reaktionen auf eine ansteigende Koffeindosis: Leistung und Nebeneffekte)
Purpose: The purpose of this study was to determine the oral dose of caffeine needed to increase muscle force and power output during all-out single multijoint movements.
Methods: Thirteen resistance-trained men underwent a battery of muscle strength and power tests in a randomized, double-blind, crossover design, under four different conditions: (a) placebo ingestion (PLAC) or with caffeine ingestion at doses of (b) 3 mg/kg body weight (CAFF3mg), (c) 6 mg/kg (CAFF6mg), and (d) 9 mg/kg (CAFF9mg). The muscle strength and power tests consisted in the measurement of bar displacement velocity and muscle power output during free-weight full-squat (SQ) and bench press (BP) exercises against four incremental loads (25%, 50%, 75%, and 90% one-repetition maximum [1RM]). Cycling peak power output was measured using a 4-s inertial load test. Caffeine side effects were evaluated at the end of each trial and 24 h later.
Results: Mean propulsive velocity at light loads (25%-50% 1RM) increased significantly above PLAC for all caffeine doses (5.4%-8.5%, P = 0.039-0.003). At the medium load (75% 1RM), CAFF3mg did not improve SQ or BP muscle power or BP velocity. CAFF9mg was needed to enhance BP velocity and SQ power at the heaviest load (90% 1RM) and cycling peak power output (6.8%-11.7%, P = 0.03-0.05). The CAFF9mg trial drastically increased the frequency of the adverse side effects (15%-62%).
Conclusions: The ergogenic dose of caffeine required to enhance neuromuscular performance during a single all-out contraction depends on the magnitude of load used. A dose of 3 mg·kg-1 is enough to improve high-velocity muscle actions against low loads, whereas a higher caffeine dose (9 mg/kg) is necessary against high loads, despite the appearance of adverse side effects.
© Copyright 2013 Medicine & Science in Sports & Exercise. Lippincott Williams & Wilkins. Alle Rechte vorbehalten.
Schlagworte: | Sportphysiologie Neurophysiologie Muskelphysiologie Skilanglauf Genussmittel |
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Notationen: | Ausdauersportarten Biowissenschaften und Sportmedizin |
Tagging: | Koffein |
DOI: | 10.1249/MSS.0b013e31829a6672 |
Veröffentlicht in: | Medicine & Science in Sports & Exercise |
Veröffentlicht: |
2013
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Jahrgang: | 45 |
Heft: | 11 |
Seiten: | 2184-2192 |
Dokumentenarten: | Artikel |
Sprache: | Englisch |
Level: | hoch |