Eur J Appl Physiol DOI 10.1007/s00421-016-3423-x
Purpose To investigate the effect of caffeine ingestion on the 3-min all-out test (3MT) performance and plasma elec- trolytes 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 rst 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 ran- domized 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 concentra- tions were drawn pretest, 1 h after ingestion, and posttest. Results Signi cant 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 deter- mined between the conditions. Compared with the PL condition, the CAF condition yielded signi cantly 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 signi cantly higher lactate concentration after the 3MT, and signi cantly lower K+ concentrations at 1 h after caffeine ingestion. There were no signi cant interac- tion effects for pH and Na+ concentrations.
Conclusions Caffeine ingestion did not change EP but improved WEP and the rate of decline in power output dur- ing short-term, severe exercise.
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