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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    • "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.
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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.
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    • "The likely cause of the lengthened time to neuromuscular fatigue is an improved intramuscular buffering of H ? ions, owing to increased carnosine concentration by means of b-alanine supplementation (Harris et al. 2006a). However, the precise physiological mechanisms by which improved H ? ion regulation would affect neuromuscular fatigue are as yet unclear (Stout et al. 2006). Recently, van Thienen et al. (2009) observed that an 8 week b-alanine supplementation programme (2–4 g day -1 ) could enhance sprint power output at the end of a simulated endurance cycle race. "
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    ABSTRACT: Chronic supplementation with β-alanine has been shown to increase intramuscular concentrations of carnosine resulting in increased muscle buffering capacity. The ergogenic potential of β-alanine has been widely demonstrated across some exercise intensities, durations and modalities, particularly those limited by muscle acidosis (i.e., high-intensity exercise between 1 and 7 min in duration). Although the effects of training on muscle carnosine are yet to be fully investigated, evidence exists to suggest that supplementation with β-alanine alongside a structured training program may result in enhanced adaptations and additive improvements in exercise performance. Furthermore, several studies have demonstrated the beneficial effects of increased intracellular and extracellular buffering capacity through cosupplementation with sodium bicarbonate. Interestingly, it has been shown that β-alanine supplementation can improve exercise performance to a similar extent in both trained and nontrained individuals, meaning β-alanine can be used as an ergogenic aid for high-intensity exercise regardless of training status. Thus, β-alanine can be considered an appropriate nutritional aid to attenuate fatigue during high-intensity exercise.
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