The receiving games (game 1, 3, 5, 7, 9 and 11) started from a forehand ground stroke, followed by 2 backhand ground strokes, a forehand ground stroke, and 2 volleys. The service games (game 2, 4, 6, 8, 10 and 12) started from a service, followed by 2 backhand ground strokes, a forehand ground stroke, and 2 volleys. The participants were asked to return to the central line during the ground strokes, and to approach to the net during volleys. A 20 sec break was allowed between each point, and a 90 sec break was allowed after game 3, 5, 7, 9 and 11. The entire simulated match

lasted approximately 50 min. Heart rate was monitored throughout the study period using a short-ranged telemeter (EXEL SPORT, Cardiosport, West Sussex, UK). The RPE was recorded using the Borg scale before and after the skill tests and each game of the simulated match. Water was given ad libitum in the first Selleck Trichostatin A trial, and the timing and amount of consumption were recorded. The same buy Vincristine timing and amount of water consumption were repeated in the second trial. The average water consumption during the trials was 1089 ± 283 ml. Blood sampling and analysis Blood samples were taken from a forearm vein by a trained nurse. The post-exercise blood samples were taken immediately after the simulated game. The

needles were rinsed with 0.2% heparin before the sampling. A plastic seal was immediately applied to the syringe after blood collection to avoid the contact with the ambient air. The blood samples were put in ice bath and sent to the laboratory for analysis immediately.

Blood [lactate] was measured with a commercial kit (Roche Diagnostics, Indianapolis, IN, USA) using an autoanalyzer (Beckman SYNCHRON LX20 PRO, Fullerton, CA, USA). Blood [HCO3 -], pH, hemoglobin, Thalidomide and base excess were analyzed using a blood gas analyzer (Synthesis 25, Instrumentation Laboratory, Lexington, MA, USA). Blood [lactate] and [HCO3 -] were adjusted to the change in plasma volume [23]. Statistical analysis All values were expressed as means ± standard deviation. A two-way analysis of variance (ANOVA) with repeated measures was used to analyze the biochemical parameters and skill test scores. The independent variables included trial (bicarbonate and placebo) and time (before and after the simulated match). The trial × time interaction effect was used to test the null hypothesis of no difference in change over time between the 2 trials. When a significant main effect was found, the Ryan-Holm-Bonferroni step-wise method was used to determine the location of the variance [24]. The effect size of a variable was calculated with the following equation: The analysis was performed with SPSS 10.0. A P-value less than 0.05 was considered statistically significant. Results Blood [HCO3 -] remained unchanged after the match in the placebo trial (pre: 27.99 ± 2.02; post: 26.37 ± 3.50 mM) but was significantly elevated in the bicarbonate trial (pre: 29.84 ± 2.16; post: 37.98 ± 3.15 mM, p < 0.