Recently, I read an excellent article by Abbie E. Smith and colleagues titled: "Effects of β-alanine Supplementation and High-intensity Interval Training on Endurance Performance and Body Composition in men; a double-blind trail (6). The authors contributed quite significantly to β-alanine research since at the time, it was the first study to investigate the concurrent effects of β-alanine supplementation and high-intensity interval training (HIIT). Participants were randomly assigned to two groups (β-alanine (BA) or placebo (PL)). Both groups were subjected to six weeks of supervised, periodized HIIT. The authors can be commended for their meticulousness, as the subjects were controlled and matched for age, height, weight and VO2 peak, and all parameters measured were clearly defined and gauged using high standards of measurement. The dose of supplementation was well below the upper limit and above the minimum required for carnosine loading in the muscle (5,7). This simple study design with a comparatively large sample size of 46, was able to strongly affirm the results attained to the testing protocols and ultimately β-alanine supplementation. The double-blind design averted observer bias and the placebo effect. The results of the investigation was that chronic β-alanine supplementation defined as greater than 3 weeks, significantly improved time to exhaustion, VO2 peak and lean body mass and total work done, when combined with HIIT. Greater adaptations where obtained in these measures with supplementation, then achievable through training alone.
The main strength of this study is in its methods, specifically, its training protocols. During the six weeks of training, participants followed a fractal periodized plan which helps prevent overtraining and facilitates progression of training intensity and training volume (8). Smith et al. used a 2:1 work to rest ratio. This ratio, being consistent across other studies (4), creates a standard that allows reproduction of the study as well as easy comparison between studies. Training sessions were supervised and well documented with a training log for each session. Total time (seconds) completed, and workload (watts) was recorded and used to calculate total training volume (kJ). Although this information was invaluable to researches for pin pointing the specific areas of fitness that saw improvements, a log also allows participants to view their own progress, possibly motivating subjects. This would create the largest possible stimulus for adaptation and allow a better expression of the supplemental β-alanine. One curious finding in the study was an unexplained increase in ventilatory threshold in the placebo group from mid to post testing, a phenomenon not seen in the supplementation group. At a significant 35 percent increase, the otherwise thorough authors said little to offset these findings. As it is known, ventilatory threshold is correlated with lactate threshold at the same corresponding level of performance or VO2 (1,2). Increases in the ventilatory and lactate thresholds are seen with adaptations to endurance training (3). The lactate threshold is reached due to the sluggishness of the aerobic system that cannot keep up with the energy demands of rapid, short bouts of high intensity exercise. The action of lactate dehydrogenase converts pyruvate into lactic acid supplying the demand for NAD by anaerobic glycolysis at the price of an associated increase in hydrogen ions. It is this increase in hydrogen ion concentration that favors diffusion out of the muscle cell into the blood where they ultimately indirectly signal chemoreceptors to increase ventilation. Consequently, the finding of improved Ventilatory threshold in the placebo group compared to the supplementation group, would be contrary to the authors hypothesis that β-alanine improves muscle buffering, since it would be expected that a potent buffer would increase the lactate threshold and subsequently the ventilatory threshold by offsetting the hydrogen ion production in the muscle. There is no controversy of the benefits of β-alanine supplementation in delaying muscular fatigue (5), however, perhaps the short term benefits in acidosis reduction are hindering a potent stimulus (acidosis) to adaptation. We request the authors revisit the long-term effects of β-alanine on adaptations to exercise such as improvements to lactate threshold and ventilatory threshold. The results of subsequent research on the effects of long-term supplementation is that though β-alanine like other buffers are successful at generating short term improvements like increasing time to exhaustion (6), it may be at the cost of hindering natural adaptative responses to the very stimulus one is trying to avoid. More solid conclusion may be formed if lactate acidosis is measured and found to be proportional to the supplementation of β-alanine. The aim of the new analysis should be include measurement of blood pH response to HIIT with and without supplementation; subsequently a more definitive causation may be determined for the increased endurance.
Since carnosine levels remain elevated in the muscle for many weeks post β-alanine supplementation (average reduction of only 2-4 percent per week) (7), trials may be conducted in the follow-up 8, 10 and 12 weeks post supplementation to allow full adaptation to take effect. Since HIIT closely mimics the start and stop nature of numerous sports, it is an invaluable training tool for improving performance (9). Furthermore, β-alanine supplementation alone has the ability to increase intramuscular carnosine content and such an elevation has been shown to improve performance (10).
This study was novel in combining HIIT and β-alanine supplementation in order to examine their concurrent effects. The authors hypothesized that β-alanine supplementation would increase intramuscular carnosine content thereby improving the quality of HIIT by reducing the accumulation of hydrogen ions, which has been associated with fatigue (5). HIIT subjects the body to a heightened anaerobic demand, due in part to the slow initiation of the aerobic system resulting in acidosis hypothesized to be buffered indirectly by b-alanine the precursor to carnosine. This is reasonable since carnosine is a potent intramuscular buffer through sequestering hydrogen ions (6). Ventilatory threshold was found to improve in the placebo group alone, the mechanisms for which can be hypothesized but remain poorly defined and warrant successive studies. Training protocols and work to rest ratio mirrored successful studies were incremental increases to training intensity and volume were sufficient to promote adaptative responses. In the study, β-alanine used in conjunction with HIIT was found to improve VO2 peak, time to exhaustion, total work done, and lean body mass in college aged men. The impartial study design employed by the authors who used double-blind measures, made it difficult to find any flaws in its execution. These results are well substantiated, owed to comparable findings of improved times to exhaustion and performance with supplementation in high intensity, short duration activities (5,6,10), were acidosis is a limiting factor. The excellent design of this study and the protocols used combined with the novel nature of the field will no doubt create a solid stepping stone for future research.
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3. Gaesser GA, Poole DC. Lactate and ventilatory thresholds: disparity in time course of adaptations to training. J Appl Physiol 1986; 61(3):999-1004.
4. Walter AA, Smith AE, Kendall KL, Stout JR, Cramer JT. Six Weeks Of High-intensity Interval Training With And Without B-alanine Supplementation For Improving Cardiovascular Fitness In Women. J Strength Cond Res 2010; 24(5):1199-1207.
5. Derave W, Mahir S, Zdemir O, Harris RC, Pottier A, Reyngoudt H, Koppo K, Wise JA, Achten E. β-alanine supplementation augments muscle carnosine content and attenuates fatigue during repeated isokinetic contraction bouts in trained sprinters. J Appl Physiol 2007; 103: 1736-1743.
6. Smith AE, Walter AA, Graef JL, Kendall KL, Moon JR, Lockwood CM, Fukuda DH, Beck TW, Cramer JT, Stout JR. Effects of β-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial. J Int Soc Sports Nutr 2010; 6:5.
7. Baguet A, Reyngoudt H, Pottier A, Everaert I, Callens S, Achten E, Derave W. Carnosine loading and washout in human skeletal muscles. J Appl Physiol 2009;106(3):837-42.
8. Brown L, Greenwood M: Periodization Essentials and Innovations in Resistance Training Protocols. J Strength Cond Res 2005; 27:80-85.
9. Laursen PG, Shing CM, Peake JM, Coombes JS, Jenkins DG. Interval training program optimization in highly trained endurance cyclists. Med Sci SPorts Exerc 2002;34:1801-7.
10. Hill CA, Harris RC, Kim HJ, Harris BD, Sale C, Boobis LH, Kim CK, Wise JA. Influence of β-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity. Amino Acids 2007;32:225-33
