The increase in blood pH was similar as in the earlier studies because the SB dose (0.3g·kg-1 body mass)

used was comparable. However, time for the first swim trial was not improved with SB or with SB + BA ingestion. In all four treatments following the swim trials, blood pH values were significantly lower compared to pre-values. Consequently, the second swim trial was performed in stronger Metabolism inhibitor acidosis than the first, and in this state the best performances were seen during SB treatment. These results in part confirm those by Gordon et al. [34], who observed that the alkalotic condition attenuates the increase in blood H+ concentration. We hypothesized that the extracellular buffering action of SB and the intracellular pH-buffering action of carnosine through BA ingestion would be additive, resulting in an increased protection against the acidosis produced during anaerobic interval

swimming. Our results appear to support the work of Hobson et al. [20] that suggested that benefits of BA supplementation may be dependent upon high intensity exercise durations lasting more than 60 s. However, see more it was a bit Rho inhibitor surprising that when SB and BA were combined the benefit observed with SB only was negated. This is difficult to explain but, although speculative, it may be related to muscle carnosine concentations. Although several studies have suggested that trained anaerobic athletes have higher muscle carnosine concentrations [35–37], the ability to enhance muscle carnosine concentration ALOX15 from training only has not been established. Therefore, the effect of supplementing for some individuals may be small. It is possible that the effect of lowering intracellular

acidity in this type of exercise is not the only factor for muscle fatigue [38]. The other possible factors for muscle fatigue may be phosphocreatine stores, maximal oxygen uptake and some neural factors. Blood lactate There were no significant differences in blood lactate concentrations between the treatment groups, although it seems to be higher with SB and SB + BA supplementation indicating increased buffering activity in muscle. The increase in peak blood lactate (change between PL and the SB groups) was about 1 mmol·l-1. This change was smaller than reported by Ibanez et al. [39] who demonstrated a difference in peak blood lactate between treatments of 2 mmol·l-1or more is needed to observe a strong and significant improvement in performance following SB supplementation. During intensive anaerobic work [40, 41], it has been shown that lactate produced in fast-twitch muscle fibers can circulate to other fast-twitch or slow-twitch fibers for conversion to pyruvate. Pyruvate, in turn, converts to acetyl-CoA for entry into the citric acid cycle for aerobic energy metabolism. Lactate shuttling between cells enables glycogenolysis in one cell to supply other cells with fuel for oxidation [42].