EXERCISE PRESCRIPTION FOR HEALTH   

Medicina dello Sport 2018 December;71(4):591-603

DOI: 10.23736/S0025-7826.18.03448-8

Copyright © 2018 EDIZIONI MINERVA MEDICA

language: English, Italian

Effects of L-arginine supplementation on neuromuscular function

Nicola DI DANIELE ¹, Maurizio CASASCO ² ✉, Annalisa NOCE ¹, Massimo SACCHETTI ³, Antonio GIANFELICI ², Valentina ROVELLA ¹, Attilio PARISI ³

¹ Unit of Internal Medicine-Center of Hypertension and Nephrology, Department of Systems Medicine, Tor Vergata University, Rome; Italy; ² Italian Federation of Sports Medicine, Rome, Italy; ³ Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Rome, Italy

BACKGROUND: The present study was aimed at testing the hypothesis that L-arginine oral supplementation may positively affect the neuromuscular function of the upper limb and the muscular performance during fatiguing exercises in healthy young individuals and adults of middle age.
METHODS: According to a double-blind randomized cross-over design, 10 young male subjects (Y; 23.4±3.0 years) and 10 adults (A; 54.3±6.2 years) assumed either L-arginine (ARG, 5 g/day) or placebo (PLA) for 7 days. Following supplementation, the force-velocity relationship and the maximal voluntary contraction (MVC) of the elbow flexor muscles were evaluated at the isokinetic dynamometer and the mean muscle fibers conduction velocity (MFCV) of the biceps brachii assessed by surface EMG. The muscular performance was also investigated during a Repeated Sprint Ability Test (RSA) performed on a cyclo-ergometer.
RESULTS: The elbow flexors force remained unchanged in young individuals while it increased in adult individuals at the higher angular velocities (120 and 240 °/s), without significant variation of the MFCV. Muscle fatigability after the isokinetic fatiguing test did not show any variation in Y while it was attenuated in A, similar to what was observed during the RSA Test.
CONCLUSIONS: L-arginine supplementation, in the tested dose, positively influences muscular performance and resistance to fatigue of healthy adult middle-aged individuals while not eliciting significant effects in the younger ones.

KEY WORDS: Arginine - Electromyography - Muscle strength - Muscular fatigue