If you’re not into lifting heavy weights, forget about building muscle. You need to push heavy weights to promote the adaptive responses in your muscle. The more intense the training, the more response you get.
The total work done in a training session helps determine how much your muscle will adapt and grow. Thus, we are always in pursuit of supplements that will increase the amount of work we can perform in each training session. In the bodybuilding documentary “Pumping Iron,” Arnold put it this way: “If you can go through this pain period, you can be a champion; these last two or three or four repetitions … that’s what makes the muscle then grow.” To get through this, you need to mentally and physically overcome significant fatigue.
There are many thoughts on what causes the pain and fatigue associated with the burn in your muscles. First, intramuscular ATP stores become depleted. This includes using up all of your creatine phosphate stores. Second, as muscle switches to glycolysis to make ATP from glucose, lactic acid and other acid metabolites build up in the muscle. These acid metabolites are thought to contribute to “the burn.” Third, the buildup of acid and the drop in pH leads to dysfunction of the energy producing enzymes and contractile apparatus of your muscle. Finally, the mind-muscle connection, otherwise known as neuromuscular function, fails with successive effort.
CARNOSINE LEVELS ON THE RISE
Although the functional recovery of our contractile function is pretty rapid from set to set, our ability to clear the acid is slower and accumulates with successive sets. One of the buffers that helps clear the acid in your muscle is a substance called carnosine. Studies have shown that carnosine levels in your muscle rise with training and may even be linked to testosterone levels. However, the rise that occurs with training is miniscule compared to the rise you can get from supplementing with its precursors.
Carnosine is made of the amino acid histidine and the non-proteinaceous amino acid beta-alanine. Beta-alanine is the rate-limiting substrate in making muscle carnosine, as histidine is a readily available amino acid in the proteins you eat. Although your body can make beta-alanine from the breakdown of pyrimidines (components of your DNA) and from aspartate metabolism in gut bacteria, supplementation is the best way to boost carnosine levels. In fact, this is much better than trying to supplement with carnosine itself.
Supplementation with up to 4 to 6.4 grams of beta-alanine per day for four weeks can raise intramuscular carnosine levels by over 60 percent and increase buffering capacity by almost 20 percent. Furthermore, lower doses of 2 to 4 grams of beta-alanine per day for up to eight weeks can raise carnosine levels by 50 percent. Higher doses over longer periods of time (up to 10 weeks) can produce an 80 percent rise in muscle carnosine levels.3
But be warned – such high doses for such long periods may be limited by side effects such as nerve sensitivity, presenting as flushing and paresthesia (pins and needles in the hands and feet). It appears as though the nerve symptoms occur with doses greater that 10 milligrams per kilogram of body mass.2
A recent dosing study published in the scientific journal of the American College of Sports Medicine suggested that ~1.2 grams of beta-alanine per day was optimal for maintaining up to 50 percent more muscle carnosine over baseline after a six-week loading phase of 3.2 grams per day (four x 800 mg doses).4
SHOULD YOU SUPPLEMENT WITH BETA-ALANINE?
A systematic review of the scientific literature published in the International Journal of Sport Nutrition and Exercise Metabolism sought to determine whether beta-alanine supplementation can actually be of benefit to athletes. Here is a summary of some of their findings.
- Beta-alanine definitely increases muscle carnosine content.
- Beta-alanine may augment aerobic training-induced improvements in aerobic performance. However, due to inconsistent literature, it can’t be concluded that beta-alanine has any effect on endurance or aerobic capacity.
- Moderate- to high-quality evidence suggests that beta-alanine supplementation increases total work done, power output, physical working capacity and fatigue threshold.
- Moderate- to high-quality studies demonstrated an increase in lean mass in the beta-alanine-treated groups over placebo. How much is attributed to the training effect or supplementation itself can’t be determined by available data.
In essence, it appears as though beta-alanine supplementation raises the anaerobic threshold and delays fatigue in subsequent working sets. It is thought that by raising the carnosine content in muscle, less metabolic acid accumulates from set to set, allowing for more work to be done in subsequent sets. The data shows that beta-alanine’s effect is best seen in later sets of a workout rather than in the first couple of sets.
POSITIVE EFFECTS ON POWER AND ANAEROBIC THRESHOLD
Researchers at the University of Central Florida. hypothesized that beta-alanine supplementation may be able to improve performance in humans through improving focus, alertness and mental function during intense and fatiguing activity. They decided to explore these effects via a study of military personnel. Supplement use, especially stimulants like caffeine and DMAA, is very high in the military due to a need to remain energetic and mentally alert. However, with the removal of supplements like DMAA from military bases, new non-stimulant supplements are being explored.
In a double-blinded study, one group of military personnel received six grams of beta-alanine per day and the other received a rice flour placebo. The fatigue program was extensive: 4km run -> 5 counter movement jumps -> 120m sprint in full gear -> 10-shot rifle protocol with anxiety provoking planned misfire -> cognitive assessment with a serial subtraction test.
What the researchers found was that beta-alanine supplementation was able to improve lower-body jump power and shooting accuracy. However, they did not measure any improvement in cognitive function or running performance. This is consistent with previous studies and the systematic review mentioned above, that show little effect of beta-alanine on endurance performance, and positive effects on improving power and anaerobic threshold in jump/sprint performance. Interestingly, the soldiers in this study had enhanced marksmanship and rate of target acquisition, suggesting that beta-alanine improved psychomotor performance.
It appears as though beta-alanine supplementation may act on your exercise fatigue at multiple levels. By improving carnosine content of muscle, it appears that beta-alanine improves buffering of metabolic acid, enhancing your ability to perform from set to set of weightlifting. Furthermore, beta-alanine may reduce your perceived exertion and exhaustion from neuromuscular fatigue. The data seems pretty strong for those looking to improve their performance in the gym. Just don’t expect it to make your morning cardio any easier.
Dr. Victor Prisk is a board certified orthopaedic surgeon and IFBB professional bodybuilder in Pittsburgh, PA. Dr. Prisk is an active member of the GNC Medical Advisory Board and creator of the “G.A.I.N. Plan.” He is an NCAA All-American gymnast, champion swing dancer and NPC Welterweight National Champion.
- Stallknecht B, et al. Lactate production and clearance in exercise. Effects of training. A mini-review. Scand J Med Sci Sports 1998;8, 127-131.
- Caruso J, et al. Ergogenic Effects of Beta-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy. Nutrients 2012;4, 585-601.
- Kendrick IP, et al. The effects of 10 weeks of resistance training combined with beta-alanine supplementation on whole body strength, force production, muscular endurance and body composition. Amino Acids 2008;34, 547-554.
- Stegen S, et al. The Beta-Alanine Dose for Maintaining Moderately Elevated Muscle Carnosine Levels. Med Sci Sports Exerc 2014; Jan 1.
- Quesnele JJ, et al. The effects of Beta-alanine supplementation on performance: a systematic review of the literature. Int J Sport Nutr Exerc Metab 2014;Feb;24(1):14-27.
- Hoffman JR, et al. Beta-alanine supplementation improves tactical performance but not cognitive function in combat soldiers. J Int Soc Sports Nutr 2014;Apr 10;11(1):15
- Murakami T and Furuse M. The impact of taurine- and beta-alanine supplemented diets on behavioral and neurochemical parameters in mice: antidepressant versus anxiolytic-like effects. Amino Acids 2010;39:427-434.