Results of this study demonstrate that 4 weeks of β-alanine supplementation during an intense military training period was effective in enhancing lower-body jump power and psychomotor performance (shooting accuracy) in soldiers of an elite IDF Combat unit, but did not appear to have any significant effects on cognitive function or running performance. While the benefits of β-alanine for athletic performance enhancement have been demonstrated in numerous studies [10, 27, 28], this investigation appears to be the first to provide evidence of β-alanine’s potential efficacy in military specific tasks.
During the 4 week study period all participants were participating in advanced military training that included combat skill development, physical work under pressure, navigational training, self-defense/hand-to-hand combat and conditioning. This training program, as expected, appeared to be quite fatiguing as significant performance decrements were seen in 4-km run performance for both groups. Previous research has shown that intense military training from one to eight weeks can result in significant decreases in strength and power [16, 18]. In addition to the physical performance decrements associated with intense military training, decreases in shooting performance  and cognitive function  have also been reported. To defend against the physical and cognitive performance decrements related to intense and sustained military action, several studies have examined the efficacy of various stimulants and other pharmacological agents [15, 31, 32]. These studies have shown that such interventions can be very effective in sustaining military performance. For instance, Lieberman and colleagues  reported that caffeine ingestion following 72 hours of sleep deprivation was able to maintain cognitive function and mood, while Estrada et al.,  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 potential side effects associated with pharmaceutical agents, and calls for a greater effort in exploring non-pharmacological alternatives for military populations have been published . 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% . Elevations in muscle carnosine has been demonstrated to enhance intracellular muscle buffering capacity and delay fatigue during high-intensity anaerobic exercise [9, 10], 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  reported that following 4 weeks of β-alanine ingestion in participants who 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. The greater power performance observed in BA compared to PL was consistent with other studies demonstrating the fatigue resistant effects of β-alanine during high-intensity activity [34–36]. Derave and colleagues  reported that 4 weeks of β-alanine supplementation (4.8 g∙day−1) was able to delay fatigue during repeated bouts of isokinetic exercise and Van Thienen and colleagues  noted improved 30-sec sprint performance following a 110-min time trial. Each of those studies demonstrated a delay in fatigue following an acute exhaustive exercise protocol. Kern and Robinson  reported enhanced anaerobic exercise performance following a prolonged period (8-weeks) of high-intensity training in athletes supplementing with β-alanine compared to a placebo. The present study provides additional support of the benefits associated with 4-weeks of β-alanine supplementation in delaying fatigue.
Shooting performance has been shown to be sensitive to acute fatiguing activity [29, 32]. Gillingham and colleagues  demonstrated that caffeine intake before and following exhaustive exercise (2.5-hr loaded march and 1.0-hr sandbar wall construction) improve target detection, marksmanship and engagement speed during simulated combat. This present study is the first to demonstrate that the fatigue resistant effects afforded by β-alanine ingestion can also improve marksmanship and target engagement speed following fatiguing exercise. Considering that this study did not measure muscle or brain carnosine concentrations, it is unclear if this played any role in the improvements observed or whether another mechanism associated with β-alanine ingestion may be responsible for the improvement in target acquisition and marksmanship.
Fatigue during sustained and highly intense combat situations may jeopardize rapid judgment in differentiating friend from foe. The subjects in the present study were required to overcome a misfire in their weapon, and then following their shooting performance complete mathematical problems while seated. The participants in BA were able to perform their 10 shots (30.2 ± 5.8 sec) faster than PL (37.7 ± 13.9 sec), but this 24.8% difference between the groups was not statistically different (p = 0.161). However, when the time was calculated relative to the number of shots on target, BA was significantly faster than PL. Whether this was related to an improved neurological benefit is not clear; however it is clear that β-alanine supplementation directly led to enhanced marksmanship and rate of target acquisition, suggestive of improved psychomotor performance. Furthermore, the misfire in the weapon was similar for all participants and similar in both Pre and Post assessment periods. It is possible that the familiarity with how to handle the misfire for both groups also contributed to the similar completion time for the 10 shots.
There were several limitations with this study. Considering that no previous studies examined the role of β-alanine on cognitive function, the statistical power analysis used to determine subject size was based upon previous studies examining physical performance. In regards to the cognitive aspects of this study, the statistical power may not have been appropriate. In addition, the benefits of performing a field study are often offset by the inability to control all aspects of the participant’s daily activity. For instance, the structure of the training did not provide an opportunity to control or record the participant’s diet. However, considering that participants were provided the same meals we made certain assumptions that the dietary intake would be similar between groups. The training schedule also forced several volunteers to miss their scheduled ingestion time for the supplement or placebo. It was in those situations where incidences of paresthesia occurred when the volunteer ingested multiple doses at the same time. Although volunteers were required to show the empty bottle and receive the following week’s supply at the end of each week, the daily control for ingestion during meals was not possible. However, this study provided a unique opportunity to examine the efficacy of this supplement under real-life conditions involving military operations. This opportunity is not common and the results provided important information for potential dietary interventions on sustaining tactical performance in stressful conditions.