Effects of acute caffeine withdrawal on habituated male runners
| Autor: | N. Warhaftig-Glynn, R. K. Hetzler, Dixie L. Thompson, E. Dowling, Arthur Weltman |
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| Rok vydání: | 1994 |
| Předmět: |
Adult
Glycerol Male medicine.medical_specialty Anaerobic Threshold Physiology Carbohydrate metabolism Placebo Loading dose Running Fats chemistry.chemical_compound Oxygen Consumption Double-Blind Method Heart Rate Physiology (medical) Internal medicine Caffeine medicine Ventilation-Perfusion Ratio Lipolysis Humans Lactic Acid Exercise physiology Exercise chemistry.chemical_classification Lactate threshold Fatty acid Substance Withdrawal Syndrome Endocrinology chemistry Lactates Respiratory Mechanics Carbohydrate Metabolism |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 8750-7587 |
| Popis: | This study investigated the effects of caffeine withdrawal on six trained caffeine-habituated male runners: age 29.8 +/- 5.8 (SD) yr, height 180.4 +/- 5.4 cm, weight 77.3 +/- 6.7 kg, maximal O2 uptake 63.0 +/- 5.4 ml.kg-1.min-1, and daily caffeine intake 674 +/- 128 mg. The subjects received a loading dose (5 mg/kg body wt) of caffeine 48 h before each testing session. They were then given (using a repeated-measures double-blind design) additional doses of caffeine (5 mg/kg body wt) or a placebo 36, 24, 12, and 2 h before testing. They ran at a velocity corresponding to their lactate threshold for 60 min in a caffeine withdrawal or caffeinated condition. Caffeine withdrawal resulted in no significant differences in absolute O2 uptake, O2 uptake relative to maximal O2 uptake, respiratory exchange ratios, or free fatty acid concentrations. Glycerol concentrations were significantly attenuated in the withdrawal condition. No significant differences were revealed in calculated substrate utilization. It was concluded that caffeine withdrawal significantly affects lipolysis but not substrate utilization during prolonged running. |
| Databáze: | OpenAIRE |
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