Arginine alpha-ketoglutarate (AAKG) is a salt of the amino acid arginine and alpha-ketoglutaric acid. It is marketed as a bodybuilding supplement. The components are intermediates in the metabolism of nitric oxides, but no reputable scientific evidence shows any benefits from taking AAKG as a dietary supplement.
As of 2008, "there [was] no research published in peer-reviewed journals to support the assertion that an increase in nitric oxide levels promotes greater muscle protein synthesis or improves muscle strength. There is also no evidence that the arginine alpha-ketoglutarate in nitric oxide supplements have any effect on nitric oxide levels in muscles."
A recent study examined the effects of AAKG supplementation on heart rate, blood pressure, blood flow, NOx/NO2 levels, and L-arginine levels. Minimal observed changes were attributed to resistance exercise used in the experimental design, not to AAKG supplementation, although arginine levels were found to have been elevated.
Another recent study found acute AAKG supplementation made no difference in endurance or blood pressure during the course of exercise. In fact, participants that took AAKG prior to exercise had compromised endurance and strength. "Because AAKG supplementation may hinder muscular endurance, the use of these supplements before resistance training should be questioned." 
- High Intensity Training by Drew Baye - NO Supplements? No Way!
- Willoughby, DS; Boucher T; Reid J; Skelton G; Clark M (Aug 2011). "Effects of 7 days of arginine-alpha-ketoglutarate supplementation on blood flow, plasma L-arginine, nitric oxide metabolites, and asymmetric dimethyl arginine after resistance exercise". International Journal of Sport Nutrition and Exercise Metabolism. 21 (4): 291–9. PMID 21813912.
- Greer, BK; BT Jones (Jul 2011). "Acute arginine supplementation fails to improve muscle endurance or affect blood pressure responses to resistance training". Journal of Strength and Conditioning Research. 25 (7): 1789–94. PMID 21399536. doi:10.1519/JSC.0b013e3181e07569.
- Campbell, Bill I.; La Bounty, Paul M.; Roberts, Mike (2004-01-01). "The Ergogenic Potential of Arginine". Journal of the International Society of Sports Nutrition. 1: 35. ISSN 1550-2783. PMC . PMID 18500948. doi:10.1186/1550-2783-1-2-35.