Effects of Twenty-Eight Days of Beta-Alanine and Creatine Monohydrate Supplementation on the Physical Working Capacity at Neuromuscular Fatigue Threshold

Department of Health and Exercise Science, University of Oklahoma, Norman, OK 73019, USA.
The Journal of Strength and Conditioning Research (Impact Factor: 2.08). 11/2006; 20(4):928-31. DOI: 10.1519/R-19655.1
Source: PubMed


The purpose of this study was to examine the effects of 28 days of beta-alanine (b-Ala) and creatine monohydrate (CrM) supplementation on the onset of neuromuscular fatigue by using the physical working capacity at neuromuscular fatigue threshold (PWC(FT)) test in untrained men. Fifty-one men (mean age +/- SD = 24.5 +/- 5.3 years) volunteered to participate in this 28-day, double-blind, placebo-controlled study and were randomly assigned to 1 of 4 groups: placebo (PLA; 34 g dextrose; n = 13), CrM (5.25 g CrM plus 34 g dextrose; n = 12), b-Ala (1.6 g b-Ala plus 34 g of dextrose; n = 12), or b-Ala plus CrM (CrBA; 5.25 g CrM plus 1.6 g b-Ala plus 34 g dextrose; n = 14). The supplement was ingested 4 times per day for 6 consecutive days, then twice per day for 22 days before posttesting. Before and after the supplementation, subjects performed a continuous incremental cycle ergometry test while a surface electromyographic signal was recorded from the vastus lateralis muscle to determine PWC(FT). The adjusted mean posttest PWC(FT) values (covaried for pretest PWC(FT) values) for the b-Ala and CrBA groups were greater than those for the PLA group (p < or = 0.05). However, there were no differences between the CrM vs. PLA, CrBA vs. b-Ala, CrM vs. b-Ala, or CrM vs. CrBA groups (p > 0.05). These findings suggested that b-Ala supplementation may delay the onset of neuromuscular fatigue. Furthermore, there appeared to be no additive or unique effects of CrM vs. b-Ala alone on PWC(FT).

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Available from: Robert F Zoeller, Jun 05, 2014
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    • "Any subject experiencing supplement-related side effects throughout the study was documented appropriately as to not affect final analyses. Participants were instructed to consume supplement doses in 16 oz of water (Stout et al. 2006a). "
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    ABSTRACT: Within the aging population, there exists a subset of individuals termed masters athletes (MA). As masters-level competition increases in popularity, MA must find methods to enhance individual athletic performance. Longitudinal beta-alanine (BA) supplementation is suggested to enhance physical capability during exercise; however, these effects have not been evaluated in MA. To examine the longitudinal effects of BA on time to exhaustion (TTE), total work completed (TWC), and lactate clearance in female MA cyclists. Twenty-two female MA (age = 53.3 ± 1.0) participated in this double-blind design. Subjects were randomly assigned to BA (n = 11; 800 mg BA + 8 g dextrose) or placebo (PLA; n = 11; 8 g dextrose) groups and supplemented 4 doses/day over 28 days. Every 7 days, subjects completed a cycling TTE at 120 % VO2max, and TWC was calculated. Blood lactate was measured at baseline, immediate post, and 20-min post each TTE. No significant differences existed between groups for any variable at baseline (p > 0.05). After 28 days supplementation, BA had greater TTE (23 vs 1 % change) and TWC (21 vs 2 % change) than PLA (p < 0.05). Following the 20-min TTE recovery, lactate was 24 % lower in BA compared to PLA (4.35 vs. 5.76 mmol/L, respectively). No differences existed for variables during intermittent weeks. 28 days of BA supplementation increased cycling performance via an enhanced time to exhaustion and total work completed with associated lactate clearance during passive rest in female MA.
    Amino Acids 08/2015; DOI:10.1007/s00726-015-2050-x · 3.29 Impact Factor
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    • "In placebo-controlled studies, β-alanine supplementation has been consistent in demonstrating significant performance benefits in both recreational and competitive athletic populations performing high-intensity activity (Hill et al. 2007; Hoffman et al. 2006, 2008a, b; Kendrick et al. 2008; Stout et al. 2006, 2007). In a double-blind, placebo-controlled study, ingestion of 6.4 and 3.2 g day −1 of β-alanine (days 1–6 and days 7–28, respectively) in 12 untrained young men for 4 weeks (high dose was titrated to the low dose following the first week of ingestion) was shown to improve physical working capacity at fatigue threshold (PWC FT ) by 14.5 % (p < 0.05) in the β-alanine group (Stout et al. 2006). This difference was significantly (p < 0.004) greater than the placebo group that showed no change in physical working capacity. "
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    ABSTRACT: During sustained high-intensity military training or simulated combat exercises, significant decreases in physical performance measures are often seen. The use of dietary supplements is becoming increasingly popular among military personnel, with more than half of the US soldiers deployed or garrisoned reported to using dietary supplements. β-Alanine is a popular supplement used primarily by strength and power athletes to enhance performance, as well as training aimed at improving muscle growth, strength and power. However, there is limited research examining the efficacy of β-alanine in soldiers conducting operationally relevant tasks. The gains brought about by β-alanine use by selected competitive athletes appears to be relevant also for certain physiological demands common to military personnel during part of their training program. Medical and health personnel within the military are expected to extrapolate and implement relevant knowledge and doctrine from research performed on other population groups. The evidence supporting the use of β-alanine in competitive and recreational athletic populations suggests that similar benefits would also be observed among tactical athletes. However, recent studies in military personnel have provided direct evidence supporting the use of β-alanine supplementation for enhancing combat-specific performance. This appears to be most relevant for high-intensity activities lasting 60-300 s. Further, limited evidence has recently been presented suggesting that β-alanine supplementation may enhance cognitive function and promote resiliency during highly stressful situations.
    Amino Acids 07/2015; DOI:10.1007/s00726-015-2051-9 · 3.29 Impact Factor
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    • "Specifically, various PWC tests have been influenced by the consumption of creatine (Stout et al., 2006; Smith et al., 2007; Zoeller, et al. 2007), arginine (Camic et al., 2010) and BA (Stout et al., 2006, 2007, 2008; Zoeller et al., 2007; Smith et al., 2009a; McCormack et al., 2013). Stout et al. demonstrated that 28 days of BA supplementation (1Á6 g per day) significantly increased the physical working capacity at fatigue threshold (PWC FT ) of young males (Stout et al., 2006) and females (Stout et al., 2007). In a follow-up study, increases in PWC FT , primarily a peripheral measurement of fatigue, resulted from 90 days of 2Á4 g BA in an elderly population (Stout et al., 2008). "
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    ABSTRACT: Beta-alanine (BA) supplementation has been shown to delay neuromuscular fatigue as a result of increased muscle carnosine concentrations. Carnosine has also been found in brain and cardiac tissue. The physical working capacity test at heart rate threshold (PWCHRT ) is a global estimate of the onset of fatigue during exercise, influenced by central and peripheral factors. The purpose of this study was to determine the effects of 28 days of BA supplementation on the PWCHRT . Thirty subjects (mean ± SD; age: 21·0 ± 2·1 years; body mass: 72·7 ± 14·5 kg; height: 170·1 ± 7·9 cm) were randomly assigned to BA (n = 15) or placebo (PL, n = 15) groups. Testing included eight to nine total visits: an enrolment day, physical screening, peak oxygen consumption (V(·) O2peak ) and two PWCHRT assessments over 4 days. Significant differences existed between BA and PL for PWCHRT (P = 0·001; mean∆: BA∆ = +24·2 watts, PL∆ = +11·2 watts), but not for V(·) O2peak (P = 0·222), time to exhaustion (TTE; P = 0·562) or ventilatory threshold (VT; P = 0·134). Results suggest that BA may increase heart rate training threshold. These results, in combination with one previous study reporting a potential effect of BA on HR, suggest that future studies should evaluate both central and peripheral aspects of fatigue with BA intake.
    Clinical Physiology and Functional Imaging 12/2013; 34(5). DOI:10.1111/cpf.12111 · 1.44 Impact Factor
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