L-Arginine supplementation does not enhance blood flow and muscle performance in healthy and physically active older women.
OBJECTIVE
The purpose of this study was to examine the effects of acute L-arginine (L-arg) supplementation on peripheral vasodilatation and muscle performance in older women.


METHODS
In a double-blind, randomized, placebo-controlled study, 20 elderly women were randomly assigned in a double-blind fashion to either an L-arg (ARG, N = 10) or placebo (PLA, N = 10) group. During the first visit, both groups underwent a Doppler ultrasound exam (to assess the femoral artery vasodilatation) at rest (baseline), and immediately before and after the isokinetic strength test (performed at 80 min after supplementation). On the second and third visits, the groups completed a battery of muscle performance tests (to assess the isometric and functional strength), initiated at the same time point (80 min after supplementation).


RESULTS
The femoral artery blood flow (ARG: 443.9 ± 42.8 vs. PLA: 373.1 ± 40.8 ml/min; P > 0.05) and area (ARG: 0.45 ± 0.03 vs. PLA: 0.41 ± 0.02 cm(2); P > 0.05) were similar between the groups at basal conditions, and they remained unchanged after supplementation. Following exercise, blood flow increased ~160 % above the basal level, and there was no significant (P > 0.05) difference between the ARG and PLA groups. Additionally, there were no significant (P > 0.05) differences between the ARG and PLA groups for any strength variable (isokinetic, isometric, and functional).


CONCLUSIONS
These results show that acute L-arg supplementation provides no ergogenic effect on blood flow and muscle performance in older women.
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil. afaguiarunesp@gmail.com.
Andreo Fernando
AF
Aguiar
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil.
Mario Carlos Welin
MC
Balvedi
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil.
Cosme Franklim
CF
Buzzachera
Department of Physical Education, Centre for Physical Education and Sports, Londrina State University (UEL), Londrina, PR, Brazil.
Leandro Ricardo
LR
Altimari
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil.
Marcell Alysson Batisti
MA
Lozovoy
Department of Physical Education, Centre for Physical Education and Sports, Londrina State University (UEL), Londrina, PR, Brazil.
Marcelo
M
Bigliassi
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil.
Renata Selvatici Borges
RS
Januário
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil.
Rafael Mendes
RM
Pereira
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil.
Vanda Cristina
VC
Sanches
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil.
Douglas Kratki
DK
da Silva
Center of Research in Health Sciences, North University of Paraná (UNOPAR), Avenue Paris, 675, Jardim Piza, Londrina, PR, CEP: 86041-120, Brazil.
Guilherme Atsushi
GA
Muraoka
D000368:Aged; D000369:Aged, 80 and over; D001120:Arginine / Q000008:administration & dosage*; D001783:Blood Flow Velocity / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D015992:Body Mass Index; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D058573:Performance-Enhancing Substances / Q000008:administration & dosage; D055070:Resistance Training; D012146:Rest; D014664:Vasodilation / Q000187:drug effects
D058573:Performance-Enhancing Substances; D009569:Nitric Oxide; D001120:Arginine
Aging; Ergogenic; Muscle; Nutritional supplementation; Strength