The Effect of 2 Weeks of Inactivated Probiotic Bacillus coagulans on Endocrine, Inflammatory, and Performance Responses During Self-Defense Training in Soldiers.

Hoffman, JR, Hoffman, MW, Zelicha, H, Gepner, Y, Willoughby, DS, Feinstein, U, and Ostfeld, I. The Effect of 2-Weeks of Inactivated Probiotic Bacillus coagulans on Endocrine, Inflammatory and Performance Responses During Self-Defense Training in Soldiers. J Strength Cond Res 33(9): 2330-2337, 2019-The effect of 2 weeks of inactivated Bacillus coagulans (iBC) ingestion on performance and inflammatory cytokines was examined during a self-defense course in soldiers. Sixteen male soldiers were randomly assigned to either iBC (n = 8) or placebo (PL; n = 8) in this double-blind study. Participants were garrisoned on base and participated in the same training tasks. Assessments were conducted in a single day before (PRE) and after the supplementation period (POST). During each testing session, participants were assessed for vertical jump power (VJP), muscle endurance, simulated casualty drag, and 2 100-m shuttle runs. Resting blood measures for testosterone, cortisol, creatine kinase, and inflammatory cytokines were also assessed. Mann-Whitney analysis of change (Δ) scores indicated no significant change (p's > 0.05) in any of the performance or blood variables. However, a trend (p = 0.089) was noted in the Δ score for VJP in iBC compared with PL. In addition, trends were observed in the change in IL-10 (p = 0.057) and IFNγ (p = 0.057). Magnitude based inferential analysis indicated that changes in VJP and simulated casualty drag were likely beneficial (90.7 and 80.4% likelihood effect, respectively) for iBC. In addition, iBC supplementation very likely augmented IL-10 concentrations, but was possibly negative for changes in IL-6, and likely negative for changes in TNFα and IFNγ. Changes in all other performance and blood markers were unclear. Results indicated that 2 weeks of iBC supplementation appeared to be beneficial for maintaining power and short-term speed performance, while attenuating the inflammatory response during intense training in a military self-defense course.

Effect of Spearmint Extract Containing Rosmarinic Acid on Physical and Executive Functioning After a Tactical Operation.

We examined the effect of a proprietary spearmint extract containing rosmarinic acid (PSE) on physical, cognitive, and executive functioning of study participants after a high-risk tactical operation while sleep deprived for 24 hours. Ten Operators (mean ± standard deviation: age, 35.1 ± 5.2 years; height, 177.6 ± 5.3cm; weight, 81.3 ± 9.3kg) from an elite counterterrorism unit volunteered to participate in this randomized, double-blind, parallel-design study. Participants were randomly assigned into either the PSE or placebo (PL) group and ingested 900mg/day PSE or an equivalent amount of PL for 17 days. Physical, cognitive, and executive functioning was tested before PST supplementation (PRE) and within 1 hour of the operation's conclusion (POST). Magnitude-based inferences indicated that differences between PSE and PL in jump power, reactive agility, eye-hand coordination, and cognition were unclear. However, subjective feelings of energy, alertness, and focus were very likely, likely, and possibly better for PSE than PL, respectively. There was no difference (ρ = .64) between groups in identifying the correct target; however, all participants in the PSE group correctly identified the target, whereas 60% of participants in the PL group correctly identified the target at POST. Although the results of this study do not provide conclusive evidence regarding the efficacy of PSE, they do suggest additional research is warranted in a larger sample of participants.

Effect of High-Dose, Short-Duration ß-Alanine Supplementation on Circulating IL-10 Concentrations During Intense Military Training.

Hoffman, JR, Gepner, Y, Hoffman, M, Zelicha, H, Shapira, S, and Ostfeld, I. Effect of high dose, short-duration ß-alanine supplementation on circulating IL-10 concentrations during intense military training. J Strength Cond Res 32(10): 2978-2981, 2018-This study examined the effect of ß-alanine as a potential anti-inflammatory agent during intense military training. Twenty soldiers (20.1 ± 0.6 years) from an elite combat unit were randomly assigned to either a ß-Alanine (BA) or placebo (PL) group. Soldiers were provided with 12 g·d of either BA or PL for 7 days between 2 intensive periods of navigational training and restricted sleep. During the initial training period, soldiers navigated on average 27.8 km·d with ∼50% of their body mass in their packs for 5 days. Soldiers returned to base and began a 7-day supplementation program before departing for an additional period of intense field training. During the second period of field training, soldiers navigated 10 km·d for an additional 5 days, carrying similar loading as the initial week, performed tactical missions, and slept approximately 5 hours per day. Blood samples were obtained after the initial training period and after the second training period and analyzed for IL-10. Magnitude-based inferences that were used to provide inferences on the true effect BA may have had on IL-10 concentrations compared with PL, calculated from 90% confidence intervals. Data analysis indicated that changes in circulating IL-10 concentrations (mean difference 0.86 pg·ml) were possibly greater (57%) for BA than PL. Results of this study suggest that 1 week of high-dose BA ingestion may enhance the anti-inflammatory response during intense military training, suggesting a potential therapeutic role of BA during intense training.

The effect of HMB ingestion on the IGF-I and IGF binding protein response to high intensity military training.

OBJECTIVE: Insulin-like growth factor-I (IGF-I) is a metabolic and anabolic biomarker that has been proposed to reflect physiological adaptations resulting from multistressor environments. The bioactivity of IGF-I is regulated by seven different insulin-like growth factor binding proteins (IGFBPs) which act not only as carriers of IGF-1, but also function as a modulator of IGF-I availability and activity. Supplementing with ß-hydroxy-ß-methylbutyrate (HMB) has been shown to enhance physiological outcomes associated with intense training, and has been reported to augment the IGF-1 response. The purpose of this study was to examine the effect of 23days of HMB supplementation on circulating levels of IGF-I and IGFBPs in combat soldiers during highly intense military training. METHODS: Thirteen male soldiers from an elite infantry unit volunteered to participate in this double-blind, parallel design study. Soldiers were provided 3g·day-1 of either HMB (n=6) or placebo (PL; n=7). During the study soldiers performed advanced military training with periods of restricted sleep and severe environmental stressors. Blood samples were obtained prior to (PRE) and approximately 18h following the final supplement consumption (POST). RESULTS: No significant differences were observed for circulating IGF-1 concentrations between HMB and PL (p=0.568). In addition, no differences were seen between the groups for IGFBP-1 (p=1.000), IGFBP-2 (p=0.855), IGFBP-3 (p=0.520), IGFBP-4 (p=0.103), IGFBP-5 (p=0.886), or IGFBP-6 (p=0.775). A significant difference was noted between HMB (169.9±23.0ng·ml-1) and PL (207.2±28.0ng·ml-1) for IGFBP-7 at POST (p=0.042). CONCLUSIONS: Although the results of this study do not support the influence of HMB supplementation on circulating concentrations of IGF-1 or IGFBPs1-6 during high intensity military training, it does present initial evidence that it may lower circulating IGFBP-7 concentrations. This may provide some indication of a reduced stress response, but further investigation on the physiological role of IGFBP-7 and military training is needed.

Spatial Awareness is Related to Moderate Intensity Running during a Collegiate Rugby Match.

The purpose of the present study was to evaluate the relationship between spatial awareness, agility, and distance covered in global positioning system (GPS) derived velocity zone classifications during a collegiate rugby match. Twelve American collegiate rugby union players (mean±SD; age: 21.2±1.4 y; weight: 85.0±16.0 kg; 7 forwards & 5 backs) on a single team volunteered to participate in this investigation. The distances travelled at low (walking/jogging; <2.7m/s), moderate (cruising/striding; 2.7-5.0 m/s), and high intensities (running/sprinting; >5.0 m/s) were measured for each player using GPS sensors and normalized according to playing time during an official USA Rugby match. Spatial awareness was measured as visual tracking speed from one core session of a 3-dimensional multiple-object-tracking speed (3DMOTS) test (1.35±0.59 cm·sec-1). Agility was assessed utilizing the pro agility (5.05±0.28 sec) and t drill (10.62±0.39 sec). Analysis of variance revealed that athletes travelled the greatest distance during walking/jogging (39.5±4.5 m·min-1) and least distance during running/sprinting (4.9±3.5 m·min-1). Pearson product moment correlations revealed that only distance covered while cruising/striding (20.9±6.5 m·min-1) was correlated to spatial awareness (r=0.798, p=0.002). Agility did not correlate to distance covered at any velocity zone or spatial awareness. Spatial awareness, as determined by 3DMOTS, appears to be related to the moderate intensity movement patterns of rugby union athletes.

ß-Hydroxy-ß-methylbutyrate attenuates cytokine response during sustained military training.

This study tested the hypothesis that of 23 days of ß-hydroxy-ß-methylbutyrate (HMB) supplementation can maintain muscle mass and attenuate the immune and inflammatory response in combat soldiers during highly intense military training. Soldiers were randomly assigned to either a HMB (n = 6) or placebo (PL; n = 7) group and provided with 3 g · day(-1) of either HMB or PL. During the final week of supplementation soldiers participated in extreme physical training, which included night navigation of 6-8 hours across difficult terrain carrying heavy loads combined with sleep deprivation (3.8 ± 3.0 h per night). Blood draws were performed prior to and following the supplementation period. Magnetic resonance imaging, which included diffusion tensor imaging sequence, was used for muscle fiber tracking analysis. Data was analyzed using a two-way mixed factorial analysis of variance. Magnitude-based inferences were used to provide inferences on the true effects that HMB may have had on the dependent variables compared to PL, calculated from 90% confidence intervals. Changes in tumor necrosis factor-α for HMB (-3.9 ± 8.2 pg · mL(-1)) were significantly lower (P = .043) compared to the change in PL (+4.0 ± 3.7 pg · mL(-1)). HMB ingestion was also very likely (92%-95% Likelihood) to lower granulocyte colony-stimulating factor and interleukin 10 compared to PL. In addition, HMB supplementation was likely (78%-87% likelihood) to reduce interferon-γ, interleukin 8, CX3CL1, and increase muscle volume for the adductor magnus (77% likelihood) compared to PL. In summary, the results of this study provides evidence that HMB supplementation may attenuate the inflammatory response to high intense military training, and maintain muscle quality.

Physical Differences Between Forwards and Backs in American Collegiate Rugby Players.

La Monica, MB, Fukuda, DH, Miramonti, AA, Beyer, KS, Hoffman, MW, Boone, CH, Tanigawa, S, Wang, R, Church, DD, Stout, JR, and Hoffman, JR. Physical differences between forwards and backs in American collegiate rugby players. J Strength Cond Res 30(9): 2382-2391, 2016-This study examined the anthropometric and physical performance differences between forwards and backs in a championship-level American male collegiate rugby team. Twenty-five male rugby athletes (mean ± SD; age 20.2 ± 1.6 years) were assessed. Athletes were grouped according to position as forwards (n = 13) and backs (n = 12) and were evaluated on the basis of anthropometrics (height, weight, percent body fat [BF%]), cross-sectional area (CSA), muscle thickness (MT), and pennation angle (PA) of the vastus lateralis (VL), maximal strength (1 repetition maximum [1RM] bench press and squat), vertical jump power, midthigh pull (peak force [PF] and peak rate of force development [PRFD]), maximal aerobic capacity (V[Combining Dot Above]O2peak), agility (pro agility, T test), speed (40-m sprint), and a tethered sprint (peak velocity [PV], time to peak velocity, distance covered, and step rate and length). Comparisons between forwards and backs were analyzed using independent t-tests with Cohen's d effect size. Forwards were significantly different from backs for body weight (90.5 ± 12.4 vs. 73.7 ± 7.1 kg, p < 0.01; d = 1.60), BF% (12.6 ± 4.2 vs. 8.8 ± 2.1%, p ≤ 0.05; d = 1.10), VL CSA (38.3 ± 9.1 vs. 28.7 ± 4.7 cm, p < 0.01; d = 1.26), 1RM bench press (121.1 ± 30.3 vs. 89.5 ± 20.4 kg, p ≤ 0.05; d = 1.17), 1RM squat (164.6 ± 43.0 vs. 108.5 ± 31.5 kg, p < 0.01; d = 1.42), PF (2,244.6 ± 505.2 vs. 1,654.6 ± 338.8 N, p < 0.01; d = 1.32), PV (5.49 ± 0.25 vs. 5.14 ± 0.37 m·s, p ≤ 0.05; d = 1.04), and step length (1.2 ± 0.1 vs. 1.1 ± 0.1 m, p ≤ 0.05; d = 0.80). V[Combining Dot Above]O2peak was significantly (p ≤ 0.05, d = -1.20) higher in backs (54.9 ± 3.9 ml·kg·min) than in forwards (49.4 ± 4.4 ml·kg·min). No differences in agility performance were found between position groups. The results of this study provide descriptive information on anthropometric and performance measures on American male collegiate championship-level rugby players offering potential standards for coaches to use when developing or recruiting players.

Evaluation of critical rest interval determined from repeated sprint ability testing.

BACKGROUND: To test if the critical power (CP) concept can be utilized to determine the critical rest interval (CRI) using repeated sprint ability (RSA) testing with varying work-to-rest ratios. METHODS: Twelve recreationally trained men (mean±SD; age 24.1±3.6 years) completed a graded exercise test and three RSA protocols with 6-second maximal sprints and varying rest intervals (12-36 s) on a cycle ergometer to determine CRI. Intermittent critical power (ICP) was calculated through the linear total work (TW) and time-to-exhaustion (TTE) relationship, whereas CRI was estimated using average work per sprint and ICP. Validation trials above and below CRI were conducted to evaluate physiological response. Repeated measures analysis of variance were used to analyze variables from RSA trials and changes in blood lactate, oxygen uptake (V̇O2), heart rate (HR), peak power, and TW throughout the validation trials. RESULTS: Blood lactate, average V̇O2, V̇O2peak, and heart rate were significantly greater below CRI (8.94±4.89 mmol/L, 2.05±0.36 L/min, 2.84±0.48 L/min, and 151.14±18.46 bpm, respectively) when compared to above CRI (6.56±3.45 mmol/L, 1.78±0.26 L/min, 2.61±0.43 L/min, and 138.14±17.51 bpm). Significant interactions were found between above and below CRI for minimal V̇O2 response and maximal HR response, which were consistent with the heavy and severe exercise intensity domains. CONCLUSIONS: The use of the work-time relationship determined from RSA testing with varying rest intervals can be used to determine CRI and may distinguish between physiological responses related to exercise intensity domains.

Altering Work to Rest Ratios Differentially Influences Fatigue Indices During Repeated Sprint Ability Testing.

This study examined the influence of recovery time on fatigue indices, performance (total work [TW], peak power [PP], and mean power [MP]), and oxygen consumption during repeated sprint ability (RSA) on a cycle ergometer. Eight recreationally-trained men performed 3 RSA protocols consisting of 10 × 6 s sprints with 12 s, 18 s, and 24 s rest intervals between each sprint. Fatigue indices were determined as percent decrement (%Dec) and rate of decline using either a log transform method or standard slope approach for TW, PP, and MP during respective RSA protocols. The maximal VO2 value in response to given sprint intervals and the minimal VO2 value in response to given rest periods (VO2 work and VO2 rest, respectively) were recorded. A repeated measures analysis of variance was used to analyze all variables. Average VO2 work was not different among rest interval trials. Average VO2 rest with 12 s rest was greater than 18 s and 24 s (2.16 ± 0.17 L · min(-1), 1.91 ± 0.18 L · min(-1), 1.72 ± 0.15 L · min(-1), respectively), while 18 s was greater than 24 s. Average TW and MP were greater with 24 s rest than 12 s (4,604.44 ± 915.98 J vs. 4,305.46 ± 727.17 J, respectively), with no differences between RSA protocols for PP. No differences in %Dec were observed. Both methods of calculating rates of decline per sprint for PP and TW were greater during 12 s than 18 s or 24 s. Since changes were only noted between the 12 s and 24 s protocols, a 6 s differential in rest intervals may not be enough to elicit alterations in TW, PP, MP, or %Dec in RSA performance. Rate of decline may be a more sensitive measure of fatigue than %Dec.

Critical Velocity Is Associated With Combat-Specific Performance Measures in a Special Forces Unit.

The purpose of this study was to examine the relationship between critical velocity (CV) and anaerobic distance capacity (ADC) to combat-specific tasks (CST) in a special forces (SFs) unit. Eighteen male soldiers (mean ± SD; age: 19.9 ± 0.8 years; height: 177.6 ± 6.6 cm; body mass: 74.1 ± 5.8 kg; body mass index [BMI]: 23.52 ± 1.63) from an SF unit of the Israel Defense Forces volunteered to complete a 3-minute all-out run along with CST (2.5-km run, 50-m casualty carry, and 30-m repeated sprints with "rush" shooting [RPTDS]). Estimates of CV and ADC from the 3-minute all-out run were determined from data downloaded from a global position system device worn by each soldier, with CV calculated as the average velocity of the final 30 seconds of the run and ADC as the velocity-time integral above CV. Critical velocity exhibited significant negative correlations with the 2.5-km run time (r = -0.62, p < 0.01) and RPTDS time (r = -0.71, p < 0.01). In addition, CV was positively correlated with the average velocity during the 2.5-km run (r = 0.64, p < 0.01). Stepwise regression identified CV as the most significant performance measure associated with the 2.5-km run time, whereas BMI and CV measures were significant predictors of RPTDS time (R(2) = 0.67, p ≤ 0.05). Using the 3-minute all-out run as a testing measurement in combat, personnel may offer a more efficient and simpler way in assessing both aerobic and anaerobic capabilities (CV and ADC) within a relatively large sample.

The effect of an acute ingestion of Turkish coffee on reaction time and time trial performance.

BACKGROUND: The purpose of this study was to examine the ergogenic benefits of Turkish coffee consumed an hour before exercise. In addition, metabolic, cardiovascular, and subjective measures of energy, focus and alertness were examined in healthy, recreationally active adults who were regular caffeine consumers (>200 mg per day). METHODS: Twenty males (n = 10) and females (n = 10), age 24.1 ± 2.9 y; height 1.70 ± 0.09 m; body mass 73.0 ± 13.0 kg (mean ± SD), ingested both Turkish coffee [3 mg · kg(-1) BW of caffeine, (TC)], and decaffeinated Turkish coffee (DC) in a double-blind, randomized, cross-over design. Performance measures included a 5 km time trial, upper and lower body reaction to visual stimuli, and multiple object tracking. Plasma caffeine concentrations, blood pressure (BP), heart rate and subjective measures of energy, focus and alertness were assessed at baseline (BL), 30-min following coffee ingestion (30+), prior to endurance exercise (PRE) and immediately-post 5 km (IP). Metabolic measures [VO2, V E , and respiratory exchange rate (RER)] were measured during the 5 km. RESULTS: Plasma caffeine concentrations were significantly greater during TC (p < 0.001) at 30+, PRE, and IP compared to DC. Significantly higher energy levels were reported at 30+ and PRE for TC compared to DC. Upper body reaction performance (p = 0.023) and RER (p = 0.019) were significantly higher for TC (85.1 ± 11.6 "hits," and 0.98 ± 0.05 respectively) compared to DC (81.2 ± 13.7 "hits," and 0.96 ± 0.05, respectively). Although no significant differences (p = 0.192) were observed in 5 km run time, 12 of the 20 subjects ran faster (p = 0.012) during TC (1662 ± 252 s) compared to DC (1743 ± 296 s). Systolic BP was significantly elevated during TC in comparison to DC. No other differences (p > 0.05) were noted in any of the other performance or metabolic measures. CONCLUSIONS: Acute ingestion of TC resulted in a significant elevation in plasma caffeine concentrations within 30-min of consumption. TC ingestion resulted in significant performance benefits in reaction time and an increase in subjective feelings of energy in habitual caffeine users. No significant differences were noted in time for the 5 km between trials, however 60 % of the participants performed the 5 km faster during the TC trial and were deemed responders. When comparing TC to DC in responders only, significantly faster times were noted when consuming TC compared to DC. No significant benefits were noted in measures of cognitive function.

Regular- and postseason comparisons of playing time and measures of running performance in NCAA Division I women soccer players.

The management of playing time in National Collegiate Athletic Association (NCAA) soccer athletes may be a key factor affecting running performance during competition. This study compared playing time and running performance between regular-season and postseason competitions during a competitive women's soccer season. Nine NCAA Division I women soccer players (age, 21.3 ± 0.9 years; height, 170.3 ± 5.7 cm; body mass, 64.0 ± 5.8 kg) were tracked using portable GPS devices across 21 games during a competitive season (regular season (n = 17); postseason (n = 4)). Movements on the field were divided into operationally distinct thresholds defined as standing/transient motion, walking, jogging, low-speed running, moderate-speed running, high-speed running, sprinting, low-intensity running, and high-intensity running. A significant increase in minutes played (+17%, p = 0.010) was observed at postseason compared with the regular season. Concomitant increases in time spent engaged in low-intensity running (LIR: +18%, p = 0.011), standing/transient motion (+35%, p = 0.004), walking (+17%, p = 0.022), distance covered while walking (+14%, p = 0.036), and at low intensity (+11%, p = 0.048) were observed. Performance comparisons between the first and second half within games revealed a significant decrease (p ≤ 0.05) in high-speed and high-intensity runs during the second half of the postseason compared with the regular season. Changes in minutes played correlated significantly with changes in absolute time spent engaged in LIR (r = 0.999, p < 0.001), standing/transient motion (r = 0.791, p = 0.011), walking (r = 0.975, p = 0.001), jogging (r = 0.733, p = 0.025), distance covered while walking (r = 0.898, p < 0.001) and low-intensity activity (r = 0.945, p < 0.001). Negative correlations were observed between minutes played and absolute time sprinting (r = -0.698, p = 0.037) and distance covered sprinting (r = -0.689, p = 0.040). Results indicate that additional minutes played during the postseason were primarily performed at lower intensity thresholds, suggesting running performance during postseason competitions may be compromised with greater playing time in intercollegiate women's soccer.

Effects of time-release caffeine containing supplement on metabolic rate, glycerol concentration and performance.

This study compared caffeine pharmacokinetics, glycerol concentrations, metabolic rate, and performance measures following ingestion of a time-release caffeine containing supplement (TR-CAF) versus a regular caffeine capsule (CAF) and a placebo (PL). Following a double-blind, placebo-controlled, randomized, cross-over design, ten males (25.9 ± 3.2 y) who regularly consume caffeine ingested capsules containing either TR-CAF, CAF, or PL. Blood draws and performance measures occurred at every hour over an 8-hour period. Plasma caffeine concentrations were significantly greater (p < 0.05) in CAF compared to TR-CAF during hours 2-5 and significantly greater (p = 0.042) in TR-CAF compared to CAF at hour 8. There were no significant differences between trials in glycerol concentrations (p = 0.86) or metabolic measures (p = 0.17-0.91). Physical reaction time was significantly improved for CAF at hour 5 (p=0.01) compared to PL. Average upper body reaction time was significantly improved for CAF and TR-CAF during hours 1-4 (p = 0.04 and p = 0.01, respectively) and over the 8-hour period (p = 0.04 and p = 0.001, respectively) compared to PL. Average upper body reaction time was also significantly improved for TR-CAF compared to PL during hours 5-8 (p = 0.004). TR-CAF and CAF showed distinct pharmacokinetics yielding modest effects on reaction time, yet did not alter glycerol concentration, metabolic measures, or other performance measures. Key pointsTime-release caffeine and regular caffeine showed distinct pharmacokinetics over an 8-hour period following ingestion.Time-release caffeine and regular caffeine yielded modest effects on reaction time over an 8-hour period following ingestion.Time-release caffeine and regular caffeine did not alter glycerol concentration, metabolic measures, or other performance measures over an 8-hour period following ingestion.

ß-Alanine ingestion increases muscle carnosine content and combat specific performance in soldiers.

The purpose of this study was to examine the effect of ß-alanine (BA) ingestion on tissue carnosine levels and the impact such changes would have on combat specific activity. Eighteen soldiers (19.9 ± 0.8 year) from an elite combat unit were randomly assigned to either a BA or placebo (PL) group. Before and following a 30-day supplementation period carnosine content of the gastrocnemius muscle and brain was determined by proton magnetic resonance spectroscopy. During each testing session, participants performed military relevant tasks that included a 2.5 km run, a 1-min sprint, 50-m casualty carry, repeated 30-m sprints with target shooting, and a 2-min serial subtraction test (SST) to assess cognitive function under stressful conditions. A significant elevation (p = 0.048) in muscle carnosine content was noted in BA compared to PL. Changes in muscle carnosine content was correlated to changes in fatigue rate (r = 0.633, p = 0.06). No changes (p = 0.607) were observed in brain carnosine content. Following supplementation, no differences were noted in 2.5 km run, 1-min sprint, repeated sprint, or marksmanship performance, but participants in BA significantly (p = 0.044) improved their time for the 50-m casualty carry and increased their performance (p = 0.022) in the SST compared to PL. In summary, 30-days of BA ingestion can increase muscle carnosine content and improve aspects of military specific performance. Although cognitive performance was significantly greater in participants consuming BA compared to placebo, current study methods were unable to detect any change in brain carnosine levels, thus, the precise mechanism underlying these effects remains elusive.

ß-alanine supplementation improves tactical performance but not cognitive function in combat soldiers.

BACKGROUND: There are no known studies that have examined ß-alanine supplementation in military personnel. Considering the physiological and potential neurological effects that have been reported during sustained military operations, it appears that ß-alanine supplementation may have a potential benefit in maintaining physical and cognitive performance during high-intensity military activity under stressful conditions. The purpose of this study was to examine the effect of 28 days of ß-alanine ingestion in military personnel while fatigued on physical and cognitive performance. METHODS: Twenty soldiers (20.1 ± 0.9 years) from an elite combat unit were randomly assigned to either a ß-alanine (BA) or placebo (PL) group. Soldiers were involved in advanced military training, including combat skill development, navigational training, self-defense/hand-to-hand combat and conditioning. All participants performed a 4-km run, 5-countermovement jumps using a linear position transducer, 120-m sprint, a 10-shot shooting protocol with assault rifle, including overcoming a misfire, and a 2-min serial subtraction test to assess cognitive function before (Pre) and after (Post) 28 days of supplementation. RESULTS: The training routine resulted in significant increases in 4-km run time for both groups, but no between group differences were seen (p = 0.597). Peak jump power at Post was greater for BA than PL (p = 0.034), while mean jump power for BA at Post was 10.2% greater (p = 0.139) than PL. BA had a significantly greater (p = 0.012) number of shots on target at Post (8.2 ± 1.0) than PL (6.5 ± 2.1), and their target engagement speed at Post was also significantly faster (p = 0.039). No difference in serial subtraction performance was seen between the groups (p = 0.844). CONCLUSION: Results of this study indicate that 4-weeks of ß-alanine ingestion in young, healthy soldiers did not impact cognitive performance, but did enhance power performance, marksmanship and target engagement speed from pre-ingestion levels.

L-alanyl-L-glutamine ingestion maintains performance during a competitive basketball game.

BACKGROUND: The purpose of this study was to examine the efficacy of L-alanyl-L-glutamine (AG) ingestion on basketball performance, including jump power, reaction time, shooting accuracy and fatigue. METHODS: Ten women (21.2 ± 1.6 years; height: 177.8 ± 8.7 cm; body mass: 73.5 ± 8.0 kg), all scholarship NCAA Division I basketball players, volunteered for this study. Subjects participated in four trials, each consisting of a 40-min basketball game with controlled time-outs for rehydration. During the first trial (DHY) subjects were not allowed to rehydrate, and the total weight lost during the contest was used to determine fluid replenishment during the subsequent three trials. During one trial subjects consumed only water (W), while during the other two trials subjects consumed the AG supplement mixed in water using either a low dose (1 g per 500 ml) (AG1) or high dose (2 g per 500 ml) (AG2) concentration. All data assessed prior to and following each game were converted into a Δ score (Post results - Pre results). All performance data were then analyzed using a one-way repeated measures analysis of variance. RESULTS: During DHY subjects lost 1.72 ± 0.42 kg (2.3%) of their body mass. No differences in fluid intake (1.55 ± 0.43 L) were seen between rehydration trials. A 12.5% (p = 0.016) difference in basketball shooting performance was noted between DHY and AG1 and an 11.1% (p = 0.029) difference was seen between AG1 and W. Visual reaction time was significantly greater following AG1 (p = 0.014) compared to DHY. Differences (p = 0.045) in fatigue, as determined by player loads, were seen only between AG2 and DHY. No differences were seen in peak or mean vertical jump power during any trial. CONCLUSION: Rehydration with AG appears to maintain basketball skill performance and visual reaction time to a greater extent than water only.

The effects of acute and prolonged CRAM supplementation on reaction time and subjective measures of focus and alertness in healthy college students.

BACKGROUND: The purpose of this study was to examine the effect of acute and prolonged (4-weeks) ingestion of a supplement designed to improve reaction time and subjective measures of alertness, energy, fatigue, and focus compared to placebo. METHODS: Nineteen physically-active subjects (17 men and 2 women) were randomly assigned to a group that either consumed a supplement (21.1 ± 0.6 years; body mass: 80.6 ± 9.4 kg) or placebo (21.3 ± 0.8 years; body mass: 83.4 ± 18.5 kg). During the initial testing session (T1), subjects were provided 1.5 g of the supplement (CRAM; α-glycerophosphocholine, choline bitartrate, phosphatidylserine, vitamins B3, B6, and B12, folic acid, L-tyrosine, anhydrous caffeine, acetyl-L-carnitine, and naringin) or a placebo (PL), and rested quietly for 10-minutes before completing a questionnaire on subjective feelings of energy, fatigue, alertness and focus (PRE). Subjects then performed a 4-minute quickness and reaction test followed by a 10-min bout of exhaustive exercise. The questionnaire and reaction testing sequence was then repeated (POST). Subjects reported back to the lab (T2) following 4-weeks of supplementation and repeated the testing sequence. RESULTS: Reaction time significantly declined (p = 0.050) between PRE and POST at T1 in subjects consuming PL, while subjects under CRAM supplementation were able to maintain (p = 0.114) their performance. Significant performance declines were seen in both groups from PRE to POST at T2. Elevations in fatigue were seen for CRAM at both T1 and T2 (p = 0.001 and p = 0.000, respectively), but only at T2 for PL (p = 0.029). Subjects in CRAM maintained focus between PRE and POST during both T1 and T2 trials (p = 0.152 and p = 0.082, respectively), whereas significant declines in focus were observed between PRE and POST in PL at both trials (p = 0.037 and p = 0.014, respectively). No difference in alertness was seen at T1 between PRE and POST for CRAM (p = 0.083), but a significant decline was recorded at T2 (p = 0.005). Alertness was significantly lower at POST at both T1 and T2 for PL (p = 0.040 and p = 0.33, respectively). No differences in any of these subjective measures were seen between the groups at any time point. CONCLUSION: Results indicate that acute ingestion of CRAM can maintain reaction time, and subjective feelings of focus and alertness to both visual and auditory stimuli in healthy college students following exhaustive exercise. However, some habituation may occur following 4-weeks of supplementation.

Examination of a pre-exercise, high energy supplement on exercise performance.

BACKGROUND: The purpose of this study was to examine the effect of a pre-exercise high energy drink on reaction time and anaerobic power in competitive strength/power athletes. In addition, the effect of the pre-exercise drink on subjective feelings of energy, fatigue, alertness and focus was also explored. METHODS: Twelve male strength/power athletes (21.1 +/- 1.3 y; 179.8 +/- 7.1 cm; 88.6 +/- 12.1 kg; 17.6 +/- 3.3% body fat) underwent two testing sessions administered in a randomized and double-blind fashion. During each session, subjects reported to the Human Performance Laboratory and were provided with either 120 ml of a high energy drink (SUP), commercially marketed as Redline Extreme(R) or 120 ml of a placebo (PL) that was similar in taste and appearance but contained no active ingredients. Following consumption of the supplement or placebo subjects rested quietly for 10-minutes prior to completing a survey and commencing exercise. The survey consisted of 4 questions asking each subject to describe their feelings of energy, fatigue, alertness and focus for that moment. Following the completion of the questionnaire subjects performed a 2-minute quickness and reaction test on the Makoto testing device (Makoto USA, Centennial CO) and a 20-second Wingate Anaerobic Power test. Following a 10-minute rest subjects repeated the testing sequence and after a similar rest period a third and final testing sequence was performed. The Makoto testing device consisted of subjects reacting to both a visual and auditory stimulus and striking one out of 30 potential targets on three towers. RESULTS: Significant difference in reaction performance was seen between SUP and PL in both average number of targets struck (55.8 +/- 7.4 versus 51.9 +/- 7.4, respectively) and percent of targets struck (71.9 +/- 10.5% versus 66.8 +/- 10.9%, respectively). No significant differences between trials were seen in any anaerobic power measure. Subjective feelings of energy (3.5 +/- 0.5 versus 3.1 +/- 0.5) and focus (3.8 +/- 0.5 versus 3.3 +/- 0.7) were significantly higher during SUP compared to PL, respectively. In addition, a trend towards an increase in average alertness (p = 0.06) was seen in SUP compared to P. CONCLUSION: Results indicate a significant increase in reaction performance, with no effect on anaerobic power performance. In addition, ingestion of this supplement significantly improves subjective feelings of focus and energy in male strength/power athletes.