The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the mechanisms and use of beta-alanine supplementation. Based on the current available literature, the conclusions of the ISSN are as follows: 1) Four weeks of beta-alanine supplementation (4–6 g daily) significantly augments muscle carnosine concentrations, thereby acting as an intracellular pH buffer; 2) Beta-alanine supplementation currently appears to be safe in healthy populations at recommended doses; 3) The only reported side effect is paraesthesia (tingling), but studies indicate this can be attenuated by using divided lower doses (1.6 g) or using a sustained-release formula; 4) Daily supplementation with 4 to 6 g of beta-alanine for at least 2 to 4 weeks has been shown to improve exercise performance, with more pronounced effects in open end-point tasks/time trials lasting 1 to 4 min in duration; 5) Beta-alanine attenuates neuromuscular fatigue, particularly in older subjects, and preliminary evidence indicates that beta-alanine may improve tactical performance; 6) Combining beta-alanine with other single or multi-ingredient supplements may be advantageous when supplementation of beta-alanine is high enough (4–6 g daily) and long enough (minimum 4 weeks); 7) More research is needed to determine the effects of beta-alanine on strength, endurance performance beyond 25 min in duration, and other health-related benefits associated with carnosine.

/pdf/international-society-of-sports-nutrition-position-stand-2safnehp11.pdf

International society of sports nutrition position stand: Beta-Alanine.

Optimization of metabolic state prior to major surgery leads to improved surgical outcomes. Nutrition screening protocols should be implemented in the preoperative evaluation, possibly as part of a bundle. Strategies to minimize hyperglycemia and insulin resistance by aggressive preoperative nutrition and carbohydrate loading may promote maintenance of a perioperative anabolic state, improving healing, reducing complications, and shortening the time to recovery of bowel function and hospital discharge. Short courses of preoperative immune-modulating formulas, using combinations of arginine, ω-3 fatty acids, and other nutrients, have been associated with improved surgical outcomes. These immune-modulating nutrients are key elements of metabolic pathways that promote attenuation of the metabolic response to stress and improve both wound healing and immune function. Patients with severe malnutrition and gastrointestinal dysfunction may benefit from preoperative parenteral nutrition. Continuation of feeding through the intraoperative period for severely stressed hypermetabolic patients undergoing nongastrointestinal surgery is another strategy to optimize metabolic state and reduce prolonged nutrition deficits. In this paper, we review the importance of preoperative nutrition and strategies for effective preoperative nutrition optimization.

Nutrition Optimization Prior to Surgery

In recent years, a new class of dietary supplements called multi-ingredient pre-workout supplements (MIPS) has increased in popularity. These supplements are intended to be taken prior to exercise and typically contain a blend of ingredients such as caffeine, creatine, beta-alanine, amino acids, and nitric oxide agents, the combination of which may elicit a synergistic effect on acute exercise performance and subsequent training adaptations compared to single ingredients alone. Therefore, the purpose of this article was to review the theoretical rationale and available scientific evidence assessing the potential ergogenic value of acute and chronic ingestion of MIPS, to address potential safety concerns surrounding MIPS supplementation, and to highlight potential areas for future research. Though direct comparisons between formulations of MIPS or between a MIPS and a single ingredient are challenging and often impossible due to the widespread use of “proprietary blends” that do not disclose specific amounts of ingredients in a given formulation, a substantial body of evidence suggests that the acute pre-exercise consumption of MIPS may positively influence muscular endurance and subjective mood, though mixed results have been reported regarding the acute effect of MIPS on force and power production. The chronic consumption of MIPS in conjunction with a periodized resistance training program appears to augment beneficial changes in body composition through increased lean mass accretion. However, the impact of long-term MIPS supplementation on force production, muscular endurance, aerobic performance, and subjective measures is less clear. MIPS ingestion appears to be relatively safe, though most studies that have assessed the safety of MIPS are relatively short (less than eight weeks) and thus more information is needed regarding the safety of long-term supplementation. As with any dietary supplement, the use of MIPS carries implications for the athlete, as many formulations may intentionally contain banned substances as ingredients or unintentionally as contaminants. We suggest that athletes thoroughly investigate the ingredients present in a given MIPS prior to consumption. In conclusion, it appears that multi-ingredient pre-workout supplements have promise as an ergogenic aid for active individuals, though further information is required regarding long-term efficacy and safety in a wider variety of populations.

/pdf/multi-ingredient-pre-workout-supplements-safety-implications-4wdx5rii18.pdf

Multi-ingredient pre-workout supplements, safety implications, and performance outcomes: a brief review.

Purpose: To critically review the methodological quality and synthesize information from systematic reviews and high quality studies on the effects of beta alanine (BA) on exercise and athletic performance. Methods: A search strategy was developed in accordance with the standards for the reporting of scientific literature via systematic reviews. Five databases were thoroughly searched from inception to November 2012. Inclusion criteria were English language, human studies, used BA to increase exercise or athletic performance, system- atic reviews or randomized controlled trials and were published in a peer-reviewed journal. Included studies were systematically graded for their methodological quality by rotating pairs of reviewers and the results were qualitatively synthesized. Results: One systematic review and 19 randomized trials were included in this review. There is one systematic review with several methodological weaknesses that limit the confidence in its results. There are moderate to high quality studies that appear to support that BA may increase power output and working capacity, decrease the feeling of fatigue and exhaustion, and have of positive effect on body composition and carnosine content. The reporting of side effects from BA supplementation in the athletic population was generally under-reported. Conclusions: There appears to be some evidence from this review that supplementation with BA may increase athletic performance. However, there is insufficient evidence examining the safety of BA supplementation and its side effects. It is therefore recommended to err on the side of caution in using BA as an ergogenic aid until there is sufficient evidence confirming its safety.

The effects of beta-alanine supplementation on performance: a systematic review of the literature.

β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former’s merits as a buffer. Carnosine normally makes a small contribution to a cell’s total buffer capacity; yet β-alanine supplementation raises intracellular carnosine concentrations that in turn improve a muscle’s ability to buffer protons. Numerous studies assessed the impact of oral β-alanine intake on muscle carnosine levels and exercise performance. β-alanine may best act as an ergogenic aid when metabolic acidosis is the primary factor for compromised exercise performance. Blood lactate kinetics, whereby the concentration of the metabolite is measured as it enters and leaves the vasculature over time, affords the best opportunity to assess the merits of β-alanine supplementation’s ergogenic effect. Optimal β-alanine dosages have not been determined for persons of different ages, genders and nutritional/health conditions. Doses as high as 6.4 g day−1, for ten weeks have been administered to healthy subjects. Paraesthesia is to date the only side effect from oral β-alanine ingestion. The severity and duration of paraesthesia episodes are dose-dependent. It may be unwise for persons with a history of paraesthesia to ingest β-alanine. As for any supplement, caution should be exercised with β-alanine supplementation.

Ergogenic Effects of β-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy

The purpose of this study was to determine the effects of the pre-workout supplement Assault™ (MusclePharm, Denver, CO, USA) on upper and lower body muscular endurance, aerobic and anaerobic capacity, and choice reaction time in recreationally-trained males. Subjective feelings of energy, fatigue, alertness, and focus were measured to examine associations between psychological factors and human performance. Twelve recreationally-trained males participated in a 3-week investigation (mean +/- SD, age: 28 +/- 5 y, height: 178 +/- 9 cm, weight: 79.2 +/- 15.7 kg, VO2max: 45.7 +/- 7.6 ml/kg/min). Subjects reported to the human performance laboratory on three separate occasions. All participants completed a baseline/familiarization day of testing that included a maximal graded exercise test for the determination of aerobic capacity (VO2max), one-rep maximum (1-RM) for bench and leg press to determine 75% of 1-RM, choice reaction tests, and intermittent critical velocity familiarization. Choice reaction tests included the following: single-step audio and visual, one-tower stationary protocol, two-tower lateral protocol, three-tower multi-directional protocol, and three-tower multi-directional protocol with martial arts sticks. Subjects were randomly assigned to ingest either the supplement (SUP) or the placebo (PL) during Visit 2. Subjects were provided with the cross-over treatment on the last testing visit. Testing occurred 20 min following ingestion of both treatments. Significant (p < 0.05) main effects for the SUP were observed for leg press (SUP: 13 ± 6 reps, PL: 11 ± 3 reps), perceived energy (SUP: 3.4 ± 0.9, PL: 3.1 ± 0.8), alertness (SUP: 4.0 ± 0.7, PL: 3.5 ± 0.8), focus (SUP: 4.1 ± 0.6, PL: 3.5 ± 0.8), choice reaction audio single-step (SUP: 0.92 ± 0.10 s, PL: 0.97 ± 0.11 s), choice reaction multi-direction 15 s (SUP: 1.07 ± 0.12 s, PL: 1.13 ± 0.14 s), and multi-direction for 30 s (SUP: 1.10 ± 0.11 s, PL: 1.14 ± 0.13 s). Ingesting the SUP before exercise significantly improved agility choice reaction performance and lower body muscular endurance, while increasing perceived energy and reducing subjective fatigue. These findings suggest that the SUP may delay fatigue during strenuous exercise.

/pdf/ingesting-a-pre-workout-supplement-containing-caffeine-b-44jn08nzjx.pdf

Ingesting a pre-workout supplement containing caffeine, B-vitamins, amino acids, creatine, and beta-alanine before exercise delays fatigue while improving reaction time and muscular endurance

Kristy R Crowley

Papers

Ingesting a pre-workout supplement containing caffeine, B-vitamins, amino acids, creatine, and beta-alanine before exercise delays fatigue while improving reaction time and muscular endurance