The use of individual amino acids by athletes is a common occurrence (see: glutamine, arginine, and branch chain amino acids-leucine, lysine, and iso-leucine-sections) as well as others are popular nutritional supplements for a variety of reasons.
One amino acid that has not gotten a great deal of attention by athletes is the amino acid L-Tyrosine. L-Tyrosine is found in high amounts in protein foods and the body can make L-Tyrosine from amino acid phenylalanine, technically making it a "non-essential" amino acid.
This often overlooked amino acid plays many important roles in human metabolism. L-Tyrosine is a precursor or "building block" to the neurotransmitters responsible for maintaining metabolic rate. L-Tyrosine is the direct precursor to stimulatory neurotransmitters such as epinephrine and noropenephrine (i.e. adrenaline) as well as certain thyroid hormones and dopamine.
Due to the fact that Tyrosine is essential to the production of all the above stimulatory hormones and neurotransmitters, some consider it an amino acid with mild stimulant-like properties to the metabolism and mental focus. Some weight loss supplements contain L-Tyrosine in an attempt to supply this essential building block in hopes it will help maintain a higher metabolism.
Though Tyrosine has not been shown to be an effective weight loss agent on its own, several studies have shown it can improve the anorectic (appetite suppressive) effects of the herbal weight loss products containing ephedrine and caffeine and OTC diet drugs containing phenylpropanolamine.
Several studies done by the US Army showed soldiers given supplemental L-Tyrosine were more resistant to cold temperatures than those not getting the amino acid. One recent study found that 21 cadets, fed 2 grams of tyrosine a day then subjected to a demanding military combat training course, reduced the effects of stress and fatigue on cognitive task performance. So, tyrosine may be a stress fighting nutrient.
It's not uncommon that people are given advice on what to eat in regards to the foods amino acid content. For example, many people have probably heard at one time or another, "if you want to be more alert, eat a high protein food." This advice is probably due to the high L-Tyrosine content of the food. Conversely, people are also given advice that to relax, they should eat foods such as milk and turkey, which are high in the amino acid L-Tryptophan.
L-Tryptophan is a building block of the neurotransmitter serotonin known to help with sleep and relaxation. Some strength athletes have found that by taking 500 to 1000mg of tyrosine prior to exercise, they have more energy, but no studies to date have found this to be an effect of Tyrosine.
However, because it may be a mild stimulant and works at the level of the central nervous system, people using MAO inhibitors, pregnant women, people with high blood pressure and people sensitive to stimulants, should probably avoid high doses of tyrosine.
For general mental focus and stress fighting, as well as pre-workout or mixed with the various weight loss agents, Tyrosine gets a thumb's up, but for any direct effects on anabolism (muscle growth) it gets a thumb's down.
Hull, K. M. and T. J Maher. "Effects of L-tyrosine on mixed-acting sympathomimetic-induced pressor actions," Pharmacol. Biochem. Behav. 43/4 (1992), p. 1047-52.
Hull, K. M. and T. J. Maher. "L-tyrosine potentiates the anorexia induced by mixed-acting sympathomimetic drugs in hyperphagic rats," Pharmacol. Exp. Ther. 255/2 (1990), p. 403-9.
Was this article helpful?
So maybe instead of being a pencil-neck dweeb, youre a bit of a fatty. Well, thats no problem either. Because this bonus will show you exactly how to burn that fat off AS you put on muscle. By boosting your metabolism and working out the way you normally do, you will get rid of all that chub and gain the hard, rippled muscles youve been dreaming of.