Pharmacokinetics, safety, and effects on exercise performance of L-arginine alpha-ketoglutarate in trained adult men.
OBJECTIVE
We evaluated the pharmacokinetics, safety, and efficacy of l-arginine alpha-ketoglutarate (AAKG) in trained adult men.


METHODS
Subjects participated in two studies that employed a randomized, double-blind, controlled design. In study 1, 10 healthy men (30-50 y old) fasted for 8 h and then ingested 4 g of time-released or non-timed-released AAKG. Blood samples were taken for 8 h after AAKG ingestion to assess the pharmacokinetic profile of L-arginine. After 1 wk the alternative supplement was ingested. In study 2, which was placebo controlled, 35 resistance-trained adult men (30-50 y old) were randomly assigned to ingest 4 g of AAKG (three times a day, i.e., 12 g daily, n = 20) or placebo (n = 15). Participants performed 4 d of periodized resistance training per week for 8 wk. At 0, 4, and 8 wk of supplementation the following tests were performed: clinical blood markers, one repetition maximum bench press, isokinetic quadriceps muscle endurance, anaerobic power, aerobic capacity, total body water, body composition, and psychometric parameters tests. Data were analyzed by repeated measures analysis of variance.


RESULTS
In study 1, significant differences were observed in plasma arginine levels in subjects taking non-timed-release and timed-release AAKG. In study 2, significant differences were observed in the AAKG group (P < 0.05) for 1RM bench press, Wingate peak power, blood glucose, and plasma arginine. No significant differences were observed between groups in body composition, total body water, isokinetic quadriceps muscle endurance, or aerobic capacity.


CONCLUSIONS
AAKG supplementation appeared to be safe and well tolerated, and positively influenced 1RM bench press and Wingate peak power performance. AAKG did not influence body composition or aerobic capacity.
Campbell
Bill
B
Exercise and Sport Nutrition Laboratory at the Center for Exercise, Nutrition, and Preventative Health Research, Department of Health, Human Performance, and Recreation, Baylor University, Waco, Texas, USA.
Roberts
Mike
M
Kerksick
Chad
C
Wilborn
Colin
C
Marcello
Brandon
B
Taylor
Lem
L
Nassar
Erika
E
Leutholtz
Brian
B
Bowden
Rodney
R
Rasmussen
Chris
C
Greenwood
Mike
M
Kreider
Richard
R
D000328:Adult; D015308:Anaerobic Threshold; D000704:Analysis of Variance; D001120:Arginine / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D001823:Body Composition / Q000187:drug effects / Q000502:physiology; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007656:Ketoglutaric Acids / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D010807:Physical Endurance; D012449:Safety; D014891:Weight Lifting / Q000502:physiology*
D003692:Delayed-Action Preparations; D007656:Ketoglutaric Acids; D001120:Arginine