These studies have shown that such interventions can be very effective in sustaining military performance. For instance, Lieberman and colleagues [15] reported that caffeine ingestion following 72 hours of sleep deprivation was able to maintain cognitive function and mood, while Estrada et al., [31] noted that helicopter pilots provided 3 doses of modafinil (a vigilance promoting drug used to treat sleepiness) at 4-hour intervals during a 40-hour period of sustained wakefulness were able to maintain alertness,

cognitive function and feelings of well-being. However, concerns have been raised regarding the safety and see more potential side effects associated with pharmaceutical agents, and calls for a greater effort in exploring non-pharmacological

PR-171 cost alternatives for military populations have been published [19]. Despite the popularity of dietary supplements in both deployed and garrisoned soldiers [20, 21], little is known regarding the efficacy of many of these supplements as they relate to specific military performance. The results of the present study demonstrate the ergogenic benefits of β-alanine ingestion on enhancing tactical performance in elite combat solders. Four weeks of β-alanine ingestion with dosages similar to the one used in the present study has been shown to elevate muscle carnosine concentrations by 60% [1]. Elevations in muscle

carnosine has been demonstrated to enhance intracellular muscle buffering capacity and delay fatigue during high-intensity anaerobic exercise [9, 10], buy SB431542 but its benefits during endurance activity has proved to be inconclusive. During the 4-km run performed in this study we were unable to show any significant advantage related to β-alanine ingestion. There have only been a limited number of studies examining the effects of β-alanine ingestion and endurance performance. Jordan and colleagues [33] reported that following 4 weeks of β-alanine ingestion in participants who Cediranib (AZD2171) were not training aerobically during the supplement period a delay in blood lactate accumulation was seen, but a decrease in aerobic capacity was also noted. The physiological role of carnosine in muscle does not provide a strong mechanism for enhancing aerobic exercise performance. However, it may increase the time spent running at higher velocities. Although our results do not support this statistically, a 34.9% difference was seen between BA and PL in the distance run at a high velocity, which warrants further exploration with larger sample sizes. Regardless, the 4-km run performed in this investigation was primarily done to increase the fatigue of the soldiers prior to the shooting and cognitive function measures. Following the 4-km run, subjects were required to perform a jump power test.