Arginine

Arginine is a non-essential amino acid that is a very popular ingredient within a lot of pre-workout "pump" supplements. It is usually found in a slightly different form (Arginine Alpha-Ketoglurate, Arginine Ethyl Ester or others) but the core reason that arginine is in these supplements is that it boosts NO (Nitric Oxide) levels which gives muscles a pumped feeling. Arginine can be mostly found in red meat, nuts and seeds within your regular diet, but for the pump effect it is best consumed as a supplement before your workout.

Arginines main function is to increase NO (Nitric Oxide) levels in supplements. This has the effect of shuttling more nutrients and protein to your muscles which encourages growth and repair. Because NO widens blood vessels arginine is also used as a sexual aid to encourage blood flow. Arginine also encourages higher levels of growth hormone, and has been linked to increased fat metabolism (by encouraging lipid oxidization). Athletes who train hard can benefit from arginines immune system enhancing properties - so you should be able to train harder and longer without illness.

Arginine is the base ingredient which causes the nitric oxide boosting effect, but it is usually combined with other chemicals to form a better delivery system. Some common examples are arginine alpha-ketoglurate and Arginine Ethyl Ester.

L-Arginine supplements are pre-workout - usually you take them 30-45mins before a workout to ensure high NO levels which results in being more vascular and more nutrients getting to the muscles. The actual dosage in most supplements is proprietary so it is unclear how much arginine you are getting, but at least 1-2g is a general guide.

As with any supplement it is possible to take too much arginine - this will lead to nausea and diarrhea, because arginine can increase stomach acids, which may inflame any ulcers. If you follow the guidelines on the label there arent any real side effects from arginine supplementation in healthy people. If you have a history of heart problems or are diabetic then it may be advisable to consult a doctor prior to taking arginine as it can increase blood sugar levels.