Some evidence suggested that NaHCO3 supplementation may alleviate the exercise-induced impairment in the neural functions. NaHCO3 supplementation has been shown to increase selleck products muscle fiber conduction velocity and reduce force decline in sustained maximal contraction after a 50-min submaximal cycling [22]. An in vitro study also revealed that alkalosis induced by high [HCO3-] resulted in an increase in twitch

tension in isolated rat phrenic nerve-hemidiaphragm after electrical stimulations [37]. Therefore, it is possible that NaHCO3 could help to restore certain level of neural functions after the simulated match, resulting in the better skilled VX-689 performance in the bicarbonate trial. The effect of NaHCO3 supplementation on neural functions requires further research. It has been argued that intracellular H+ and lactate may not be the major factors in muscular Selleck C59 wnt fatigue [38–41]. Similarly, this study showed that NaHCO3 supplementation could prevent fatigue-induced decline in performance on the condition of moderate blood [lactate] and unchanged blood pH. The predominant energy

source of the short, high-intensity strokes in the Loughborough Tennis Skill Test is phosphocreatine (PCr) because blood [lactate] was only 0.9 ± 0.1 mM after the test [4]. Some studies have proposed that the supplementation of NaHCO3 could reduce PCr degradation and increase the power output required to induce the onset of rapid increase in [inorganic phosphate (Pi)]/[PCr] in forearm muscles during incremental wrist-flexion exercise to volitional fatigue [42, 43]. However, creatine supplementation had no effect on power and accuracy of tennis strokes in studies of which test protocols were similar to the present study [44, 45]. These results suggested that muscle acidosis and creatine Casein kinase 1 content may not be the major factors in the decline in skilled tennis performance

as exemplified in this study. The Loughborough Tennis Skill Test is an optimal method for measuring the fatigue-induced decline in tennis skills as the accuracy of service and groundstroke was significantly declined after volitional fatigue [4]. In addition, the groundstroke accuracy was significantly decreased after the middle of the test [6]. Our results also showed that the consistency of service and forehand ground stroke was impaired after a simulated match in the placebo trial, while it was maintained in the bicarbonate trial. The current study presented the similar skill level of players to those in the previous studies [4, 6]. In Davey et al. [4] the average accuracy and consistency scores of service (out of 20) were 4.0 and 9.0, respectively. The average accuracy and consistency scores (out of 20) were 1.5 and 11.3 for forehand ground stroke and 1.8 and 10.