Ching-Feng Cheng1, Wei-Chieh Hsu2, Yu-Hsuan Kuo3, Ming-Tsung Shih1, Chia-Lun Lee4. 1. Department of Athletic Performance, National Taiwan Normal University, Taipei, Taiwan. 2. Graduate Institute of Sports Training, University of Taipei, Taipei, Taiwan. 3. Department of Physical Education, National Taiwan Normal University, Taipei, Taiwan. 4. Center for General Education, National Sun Yat-sen University, No. 70, Lienhai Rd., Kaohsiung, 80424, Taiwan. karenlee1129@gmail.com.
Abstract
PURPOSE: To investigate the effect of caffeine ingestion on the 3-min all-out test (3MT) performance and plasma electrolytes in athletes. METHODS:Fifteen collegiate male basketball players were recruited and completed two trials separated by at least 1 week in caffeine (CAF, 6 mg kg(-1)) and placebo conditions. During the first visit, participants performed an incremental cycling test to determine their 3MT resistance. After a familiarization trial, participants performed a CAF or PL trial according to a randomized crossover design. One hour after ingesting capsules, the participants performed the 3MT to estimate the end-test power (EP) and work done above EP (WEP). Blood samples for sodium (Na(+)), potassium (K(+)), pH, and lactate concentrations were drawn pretest, 1 h after ingestion, and posttest. RESULTS: Significant differences in WEP (CAF vs. PL, 13.4 ± 3.0 vs. 12.1 ± 2.7 kJ, P < 0.05) but not in EP (CAF vs. PL, 242 ± 37 vs. 244 ± 42 W, P > 0.05) were determined between the conditions. Compared with the PL condition, the CAF condition yielded significantly higher power outputs (60-150 s), a lower fatigue rate during the 3MT (CAF vs. PL, 0.024 ± 0.007 vs. 0.029 ± 0.006 s(-1), P < 0.05), a significantly higher lactate concentration after the 3MT, and significantly lower K(+) concentrations at 1 h after caffeine ingestion. There were no significant interaction effects for pH and Na(+) concentrations. CONCLUSIONS:Caffeine ingestion did not change EP but improved WEP and the rate of decline in power output during short-term, severe exercise.
RCT Entities:
PURPOSE: To investigate the effect of caffeine ingestion on the 3-min all-out test (3MT) performance and plasma electrolytes in athletes. METHODS: Fifteen collegiate male basketball players were recruited and completed two trials separated by at least 1 week in caffeine (CAF, 6 mg kg(-1)) and placebo conditions. During the first visit, participants performed an incremental cycling test to determine their 3MT resistance. After a familiarization trial, participants performed a CAF or PL trial according to a randomized crossover design. One hour after ingesting capsules, the participants performed the 3MT to estimate the end-test power (EP) and work done above EP (WEP). Blood samples for sodium (Na(+)), potassium (K(+)), pH, and lactate concentrations were drawn pretest, 1 h after ingestion, and posttest. RESULTS: Significant differences in WEP (CAF vs. PL, 13.4 ± 3.0 vs. 12.1 ± 2.7 kJ, P < 0.05) but not in EP (CAF vs. PL, 242 ± 37 vs. 244 ± 42 W, P > 0.05) were determined between the conditions. Compared with the PL condition, the CAF condition yielded significantly higher power outputs (60-150 s), a lower fatigue rate during the 3MT (CAF vs. PL, 0.024 ± 0.007 vs. 0.029 ± 0.006 s(-1), P < 0.05), a significantly higher lactate concentration after the 3MT, and significantly lower K(+) concentrations at 1 h after caffeine ingestion. There were no significant interaction effects for pH and Na(+) concentrations. CONCLUSIONS:Caffeine ingestion did not change EP but improved WEP and the rate of decline in power output during short-term, severe exercise.
Authors: Scott C Forbes; Darren G Candow; Jonathan P Little; Charlene Magnus; Philip D Chilibeck Journal: Int J Sport Nutr Exerc Metab Date: 2007-10 Impact factor: 4.599
Authors: Nanci S Guest; Trisha A VanDusseldorp; Michael T Nelson; Jozo Grgic; Brad J Schoenfeld; Nathaniel D M Jenkins; Shawn M Arent; Jose Antonio; Jeffrey R Stout; Eric T Trexler; Abbie E Smith-Ryan; Erica R Goldstein; Douglas S Kalman; Bill I Campbell Journal: J Int Soc Sports Nutr Date: 2021-01-02 Impact factor: 5.150