title: Caffeine ingestion improves power output decrement during 3-min all-out exercise.
abstract: OBJECTIVE
  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.affiliation: Department of Athletic Performance, National Taiwan Normal University, Taipei, Taiwan.
authors.forename: Ching-Feng
authors.initials: CF
authors.lastname: Cheng
authors.affiliation: Graduate Institute of Sports Training, University of Taipei, Taipei, Taiwan.
authors.forename: Wei-Chieh
authors.initials: WC
authors.lastname: Hsu
authors.affiliation: Department of Physical Education, National Taiwan Normal University, Taipei, Taiwan.
authors.forename: Yu-Hsuan
authors.initials: YH
authors.lastname: Kuo
authors.affiliation: Department of Athletic Performance, National Taiwan Normal University, Taipei, Taiwan.
authors.forename: Ming-Tsung
authors.initials: MT
authors.lastname: Shih
authors.affiliation: Center for General Education, National Sun Yat-sen University, No. 70, Lienhai Rd., Kaohsiung, 80424, Taiwan. karenlee1129@gmail.com.
authors.forename: Chia-Lun
authors.initials: CL
authors.lastname: Lee
mesh_terms: D000284:Administration, Oral; D002110:Caffeine / Q000008:administration & dosage*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004735:Energy Transfer / Q000187:drug effects / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology*; D010807:Physical Endurance / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
chemical_list: D002110:Caffeine
keywords: Anaerobic power; Critical power; Ergogenic aid; Nutritional supplement; Performance; Short-term high-intensity exercise