The body building supplement industry is built largely upon hype, with an occasional secondary nod to science-based results. In contrast with the beneficial effects of caffeine on power output in parallel with barbell displacement velocity, BA supplementation seems to increase power through an increased training volume without affecting the relationship between intensity and velocity.
However, depending on the duration and intensity of the exercise bout, amino acid oxidation can provide from a few to ∼10% of the total energy expenditure ( 17 ). Alternatively, uptake of β-alanine into nonmuscle tissue, such as nervous tissue, may also account for a portion of the available β-alanine after ingestion ( 15 ). However, the alternate fate of β-alanine is unknown and, therefore, warrants future investigation.
Just ∼1.2g of beta alanine per day can keep muscle carnosine levels elevated at 30-50% above baseline, resulting in improvements in muscular endurance, and high-intensity cardiovascular exercise performances, by reducing the impact of acidity on the muscles.
Β-alanine supplementation did not produce a significant ergogenic effect in these sport-specific trials ( 4,12,30,48,54 ). Baguet et al. ( 4 ) beta alanine reported a 2.7-second improvement in 2,000-m rowing ergometer performance in elite Belgian rowers after 7 weeks of β-alanine supplementation.
An analysis of amino acid sequences of other NMTases of plant origin—phosphoethanolamine NMTase, Rubisco NMTase, and putrescine NMTase—indicated that their theoretical pIs fall between 4.69 and 6.20 and their molecular mass between 37 and 56 kD. Purification and characterization of the NMTase involved in β-Ala betaine synthesis opened up opportunities for cDNA cloning, biochemical characterization of this NMTase, and understanding the functional significance of this pathway.
Thus, these findings suggest that despite the beneficial effects of β-alanine supplementation on high intensity exercise capacity 9 - 10 , β-alanine supplementation does not influence longer duration (30 min - 1 hr), lower intensity, cycling performance.
This includes elucidating the type of sports and environments, where β-alanine supplementation may be most useful and refining the strategy on how it is supplemented, with particular focus on the length of supplementation protocols to allow coaches and athletes to make more informed decisions about employing β-alanine supplementation as a worthwhile ergogenic aid.
If calcium handling were the main mechanism for an effect of elevated muscle carnosine on exercise performance, significant effects of β-alanine supplementation would be expected across a wider range of exercise performance tests than have currently been shown 2 , 9 Whilst the present study was not designed to examine the mechanisms related to increased exercise performance as a result of elevated muscle carnosine levels, the lack of an effect of β-alanine would be consistent with the lack of an effect of carnosine on calcium handling.
The variability in carnosine loading in response to β-alanine supplementation has led to individuals being categorized into low- and high-responders ( 7 ). Baguet et al. ( 4 ) reported a positive correlation between high baseline muscle carnosine content and the increase in muscle carnosine after β-alanine supplementation in elite rowers.
During exercise, the body relies on 3 energy systems that work sequentially through the varying stages of intensity, of which during exercise of high intensity we can only maintain a certain intensity level for up to 3 minutes before lactic acid raises too fast for how quick we can remove it. In doing so, lactic acid causes muscular acidosis and our internal energy systems no longer have the ability to keep with the demand of toxic removal in conjunction with reproducing usable energy known as ATP.
Lending support to this assertion, studies have examined the effects of β-alanine on exercise capacity, using tests designed to induce large increases in intramuscular hydrogen cation levels and reductions in pH 11 - 12 , 30 , and have shown significant increases in exercise capacity.
Most studies have used doses of between 3.2 and 6.4 g•d-1 of β-alanine, with this resulting in increases of 40 to 80% in the muscle carnosine concentration, depending upon the duration of supplementation and the method of determining the muscle carnosine content.