Dietary supplements containing L-arginine have no benefit for improved muscular performance, according to a study in the Journal of the Society of Sports Nutrition.
Benjamin Wax of Mississippi State University and his team examined the ingestion of L-arginine alpha-ketoglutarate (AAKG) on muscular strength and endurance in resistance trained and untrained men.
Authors: No improvement in muscle training
The authors said that L-arginine-containing supplements are generally marketed as “nitric oxide stimulators” which can increase muscular strength and endurance because an arginine boost improves blood flow through enzyme nitric oxide synthase.
“However, in the current study, acute AAKG supplementation provided no ergogenic benefit, regardless of the subjects’ training status,” said the authors.
“Based on the current study an acute ingestion of AAKG is not recommended for healthy individuals to increase maximal strength and muscular endurance for resistance training exercises,” they continued.
Method
To reach these conclusions the researchers instructed eight resistance trained and eight untrained healthy males to rotate between taking 3000 mg of AAKG or a placebo 45 minutes before doing a designed exercise regime involving a bar bell bench press and a leg press.
The participants’ heart rates were measured before and after exercise and the researchers recorded the number of repetitions achieved.
Performance was seen to be practically identically for both AAKG and placebo supplementation in both trained and untrained young men.
The results go contrary to earlier studies from Campbell et al., Elam et.al and Stanto et al, which found that L-arginine-containing supplements could aid muscle strength and endurance.
The authors of the present study declared no competing interests.
