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Beta-Alanine clinically proven to enhance performance in endurance athletes
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With its release of OptygenHPTM in August of 2007, First EnduranceTM introduced the endurance training and racing market to beta-alanine-enhanced supplements. Since then, three additional clinical studies have shown significant endurance performance benefits from beta-alanine. Now positioned as the most promising nutrient since creatine and supported with over 10 positive clinical studies, beta-alanine has become widely accepted as a highly effective nutrient for endurance training and racing. More recent studies have clearly shown it to be an effective tool to boost endurance training and racing through its effect on working capacity, VO2 and lactate threshold. (Pottier 2007, Stout 2007, Suzuki 2002, Van Thienen 2009, Zoeller 2006, and Smith 2009).
Based on current research, beta-alanine’s primary role appears to be its effect on lactate threshold – in endurance training, defined as the rate at which there is equilibrium in lactic acid production and lactic acid elimination. During exercise, hydrogen ions (H+) are produced in the body and cause the pH levels in the muscles to drop. When pH levels in the muscles are low, it means muscle tissue is acidic or producing lactic acid. At this lower pH, muscles cannot balance lactic acid production with lactic acid elimination, resulting in an overall slowing of movement, physical strength and intensity. When pH levels are balanced, training can continue for longer periods at increased intensity.
Exerting effort above the lactate threshold prevents endurance athletes from sustaining that effort for more than a few minutes. It’s long been understood that the amino acid carnosine plays a key role in the homeostasis of pH and lactate threshold, and carnosine levels are regulated by beta-alanine.
To understand how beta-alanine works, you must first understand how carnosine works.
Carnosine enters the digestive system and is hydrolyzed into histidine and beta-alanine, which is then synthesized back into carnosine by skeletal muscle. Intra-muscular carnosine buffers hydrogen ions, which in turn leads to an increase in pH – necessary for the balance between production and elimination of lactic acid.
Carnosine works by soaking up hydrogen ions (H+) to prevent low pH levels, which is confirmed by recent studies. Increased carnosine concentration in muscles leads to increased buffering capacity of intra-muscular hydrogen ion (H+) (Dunnet 1999 & 2002, Hill 2007), as well as regulation of intra-cellular pH of both oxidative and glycolytic muscle fibers (Damon 2003). Increased carnosine accounts for up to 30% of the pH buffering capacity of the body.
With intense training, athletes have an opportunity to improve their intra-muscular carnosine content by up to 87% (Harris, 2005), which in turn provides an increase in lactate threshold. However, though endurance training increases intra-muscular carnosine levels, oral supplementation of carnosine does not have the same result. So, even though carnosine is widely available as a supplement, it is only through the availability of beta-alanine that intra-muscular carnosine can increase.
A related study shows carnosine levels significantly drop with age, which may be a key reason older athletes tend to have a lesser ability to eliminate lactate. (Dunnett, 2002)
So where does beta-alanine come in?
Since beta-alanine is the precursor to the production of intra-muscular carnosine, it must be present in order for intra-muscular carnosine levels to increase when intense training takes place. Ingestion of beta-alanine for four to eight weeks has been shown to elevate muscle carnosine content by 42%, 47%, 64% and 65% respectively (Pottier 2007, Harris 2006, Hill 2007). Increasing intra-muscular carnosine means the body is capable of buffering more hydrogen and eliminating more lactic acid. The end result for an athlete is an improved lactate threshold.
What does this all mean to your performance?
The ability to sustain efforts above lactate threshold is the primary benefit associated with beta-alanine supplementation. Beta-alanine supplements should be consumed daily during heavy training blocks, and, based on today’s research, a minimum of four weeks is required before experiencing any significant increases in intra-muscular carnosine levels. Studies have proven the effect to be dose dependent, with an increased dosage pattern throughout the supplementation period. The buffering effects can be expected to slowly increase from the beginning of training, and sustained throughout the entire training block. Using this supplementation strategy to improve interval workouts or threshold training workouts is the best method to achieve a lasting physiological change that can be carried over into races.
A slew of research studies on the mechanism of improved lactate threshold through the supplementation of beta-alanine have shown significant improvements in power, strength, endurance performance, and aerobic metabolism (Smith 2009, Van Thienen 2009, Stout 2007, Suzuki 2002, Pottier et al 2007). These double-blind, placebo-controlled studies were conducted in 4 and 8 week periods.
1) Van Theinen’s 2009 study done on trained cyclists showed beta-alanine can improve sprint performance at the end of an exhaustive endurance exercise by 11.4%.
2) The Smith 2009 double-blind study done on recreationally active college men supplementing with beta-alanine for six weeks while undergoing high-intensity interval training (HIIT) showed significant improvements in VO2peak, VO2 time to fatigue versus a group using a placebo.
3) The Stout 2007 double-blind study done on 22 trained women supplementing with beta-alanine for 28 days performing on cycle ergometers showed a significant improvement in ventilatory threshold, physical working capacity at fatigue threshold and time to exhaustion.
4) The Suzuki 2002 study looked at untrained men and trained them two days per week on cycle ergometers for 8 weeks. This double-blind study showed significant increase in sustainability of high power during 30-second maximal cycle ergometer sprinting.
5) Pottier et al. 2007 investigated supplementation of beta-alanine on fifteen trained men in a 400m sprint and knee extension to exhaustion. Beta-alanine supplementation increased carnosine levels by 47% and attenuated fatigue in repeated bouts of exhaustive exercise.
1) Dunnett M., R.C. Harris. Influence of oral beta-alanine and L-histidine supplementation on the carnosine content of the gluteus medius. Equine Vet J. 30 (suppl): 499-504, 1999.
2) Dunnett M., Harris RC, Dunnett CE, Harris PA. Plasma carnosine concentration: Diurnal variation and effects of age, exercise and muscle damage. Equine Vet J Suppl; Sept 2002. (34): 283-7
3) Harris R. C. Muscle Carnosine elevation with supplementation and training, and the effects of elevation on exercise performance. (ISSN conference, 2005).
4) Harris RC, et al; The absorption of orally supplied beta-alanine and its effect on muscle carnosine sythesis in human vastus lateralis. Amino Acids; 2006 May; 30 (3): 279-289.
5) Hill CA, Harris RC, Kim HJ, Harris BD, Sale C, Boobis LH, Kim CK, Wise JA; Influence of beta-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity. Amino Acids. 2007 Feb: 32(2) 225-33
6) Pottier, A, Ozdemir M, Reyngoudt H, Koppo K, Hrris R, Wise J, Achten E, Derave W. Beta-Alanine supplementation augments muscle carnosine contenct and attenuates fatigue in trained sprinters. Medicine and Health Sciences, Belgium; ECSS July 2007.
7) Smith AE, Walter AA, Graef JL, Kendall KL, Moon JR, Lockwood CM, Fakuda DH, Beck TW, Cramer JT, Stout JR; Effects of Beta-Alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial. JISSN 6:5 2009.
8)Stout JR, Cramer JT, Soeller RF, Torok D, Costa P, Hoffman JR, Harris RC, O’Koy J.; Effects of beta-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women. Amino Acids 2007 April; 32 93): 381-6
9) Suzuki Y, Ito O, Mukai N, Takahashi H,; High levels of skeletal muscle carnosine contributes to the latter half of exercise performance during 30s maximal cycle ergometer sprinting. Jap Journal of Physiology 52 199-205, 2002.
10) Van Thienen R, Van Proeyen K, Vanden EB, Puype J, Lefere T, Hespel P. Beta-Alanine improves sprint performance in endurance cycling. Med Science Sports and Exercise; April 2009; 41(4): 898-903
11) Zoeller RF, Stout JR, O’Kroy JA, Torok DJ, Mielke M.; Effects of 28 days of beta-alanine and creatine monohydrate supplementation on aerobic power, ventilatory and lactate thresholds, and time to exhaustion. Amino Acids. 2006 Sept 5.
Ultima modifica di WNC2 : 26-08-2011 alle ore 09:46:56