Effects of twenty-eight days of beta-alanine and creatine monohydrate supplementation on the physical work 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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    • "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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    • "As such, future investigations should make every attempt to ensure the purity of the supplement used through independent analysis of the product. Where such efforts have been made, this should be included in the manuscript [see Sale et al. (2011) and Stout et al. (2006) for examples of good practice], allowing the reader to have full confidence in the data reported. b-alanine causes paraesthesia in some individuals (Harris et al. 2006), a side effect which ethically should be included in participant information sheets issued to prior to participation in all studies. "
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    ABSTRACT: Due to the well-defined role of β-alanine as a substrate of carnosine (a major contributor to H+ buffering during high-intensity exercise), β-alanine is fast becoming a popular ergogenic aid to sports performance. There have been several recent qualitative review articles published on the topic, and here we present a preliminary quantitative review of the literature through a meta-analysis. A comprehensive search of the literature was employed to identify all studies suitable for inclusion in the analysis; strict exclusion criteria were also applied. Fifteen published manuscripts were included in the analysis, which reported the results of 57 measures within 23 exercise tests, using 18 supplementation regimes and a total of 360 participants [174, β-alanine supplementation group (BA) and 186, placebo supplementation group (Pla)]. BA improved (P=0.002) the outcome of exercise measures to a greater extent than Pla [median effect size (IQR): BA 0.374 (0.140-0.747), Pla 0.108 (-0.019 to 0.487)]. Some of that effect might be explained by the improvement (P=0.013) in exercise capacity with BA compared to Pla; no improvement was seen for exercise performance (P=0.204). In line with the purported mechanisms for an ergogenic effect of β-alanine supplementation, exercise lasting 60-240 s was improved (P=0.001) in BA compared to Pla, as was exercise of >240 s (P=0.046). In contrast, there was no benefit of β-alanine on exercise lasting <60 s (P=0.312). The median effect of β-alanine supplementation is a 2.85% (-0.37 to 10.49%) improvement in the outcome of an exercise measure, when a median total of 179 g of β-alanine is supplemented.
    Amino Acids 01/2012; 43(1):25-37. DOI:10.1007/s00726-011-1200-z · 3.29 Impact Factor
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