Creatine increases muscle mass, strength and power, while arginine alpha-ketoglutarate, a precursor for nitric oxide production, improves blood flow and nutrient delivery to muscles.
Researchers at the University of Saskatchewan in Canada gave 35 men, average age 23, a supplement containing creatine, arginine, glutamine, taurine, branched-chain amino acids and medium-chain triglycerides, creatine alone or a placebo.
They measured body composition, muscular endurance (via a bench press exercise) and peak and average power (using a stationary cycling test) before and after supplementation.
Bench press reps over 3 sets increased with creatine and arginine and creatine alone. Peak power output significantly increased with creatine and arginine, but not with creatine alone. Placebo had no changes.
They concluded that creatine alone and in combination with arginine improves upper body muscular endurance and creatine plus arginine improves peak power output.