| Autor: |
Gonzalez AM; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Hoffman JR; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Wells AJ; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Mangine GT; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Townsend JR; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Jajtner AR; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Wang R; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Miramonti AA; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Pruna GJ; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., LaMonica MB; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Bohner JD; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Hoffman MW; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Oliveira LP; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Fukuda DH; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Fragala MS; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA., Stout JR; Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida , Orlando, FL USA. |
| Abstrakt: |
This study compared caffeine pharmacokinetics, glycerol concentrations, metabolic rate, and performance measures following ingestion of a time-release caffeine containing supplement (TR-CAF) versus a regular caffeine capsule (CAF) and a placebo (PL). Following a double-blind, placebo-controlled, randomized, cross-over design, ten males (25.9 ± 3.2 y) who regularly consume caffeine ingested capsules containing either TR-CAF, CAF, or PL. Blood draws and performance measures occurred at every hour over an 8-hour period. Plasma caffeine concentrations were significantly greater (p < 0.05) in CAF compared to TR-CAF during hours 2-5 and significantly greater (p = 0.042) in TR-CAF compared to CAF at hour 8. There were no significant differences between trials in glycerol concentrations (p = 0.86) or metabolic measures (p = 0.17-0.91). Physical reaction time was significantly improved for CAF at hour 5 (p=0.01) compared to PL. Average upper body reaction time was significantly improved for CAF and TR-CAF during hours 1-4 (p = 0.04 and p = 0.01, respectively) and over the 8-hour period (p = 0.04 and p = 0.001, respectively) compared to PL. Average upper body reaction time was also significantly improved for TR-CAF compared to PL during hours 5-8 (p = 0.004). TR-CAF and CAF showed distinct pharmacokinetics yielding modest effects on reaction time, yet did not alter glycerol concentration, metabolic measures, or other performance measures. Key pointsTime-release caffeine and regular caffeine showed distinct pharmacokinetics over an 8-hour period following ingestion.Time-release caffeine and regular caffeine yielded modest effects on reaction time over an 8-hour period following ingestion.Time-release caffeine and regular caffeine did not alter glycerol concentration, metabolic measures, or other performance measures over an 8-hour period following ingestion. |
