Research Paper Volume 11, Issue 10 pp 3315—3332

Effect of chronic nitrate and citrulline supplementation on vascular function and exercise performance in older individuals

Thibault Le Roux-Mallouf 1, , Felix Pelen 1, , Angela Vallejo 1, , Idir Halimaoui 1, , Stéphane Doutreleau 1, 2, , Samuel Verges 1, 2, ,

  • 1 Université Grenoble Alpes, Inserm, HP2 Laboratory, F-38000, Grenoble, France
  • 2 Sport and Pathologies Unit, Grenoble Alpes University Hospital, Hôpital Michallon, F-38042, Grenoble, France

received: November 29, 2018 ; accepted: May 17, 2019 ; published: May 29, 2019 ;

https://doi.org/10.18632/aging.101984
How to Cite

Copyright: Le Roux-Mallouf et al. This is an open‐access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Increased nitric oxide (NO) bioavailability may improve exercise performance and vascular function. It remains unclear whether older adults who experience a decreased NO bioavailability may benefit from chronic NO precursor supplementation. This randomised, double-blind, trial aims to assess the effect of chronic NO precursor intake on vascular function and exercise performance in older adults (60-70 years old). Twenty-four healthy older adults (12 females) performed vascular function assessment and both local (knee extensions) and whole-body (incremental cycling) exercise tests to exhaustion before and after one month of daily intake of a placebo (PLA) or a nitrate-rich salad and citrulline (N+C, 520mg nitrate and 6g citrulline) drink. Arterial blood pressure (BP) and stiffness, post-ischemic, hypercapnic and hypoxic vascular responses were evaluated. Prefrontal cortex and quadriceps oxygenation was monitored by near-infrared spectroscopy. N+C supplementation reduced mean BP (-3.3mmHg; p=0.047) without altering other parameters of vascular function and oxygenation kinetics. N+C supplementation reduced heart rate and oxygen consumption during submaximal cycling and increased maximal power output by 5.2% (p<0.05), but had no effect on knee extension exercise performance. These results suggest that chronic NO precursor supplementation in healthy older individuals can reduce resting BP and increase cycling performance by improving cardiorespiratory responses.

Abbreviations

NO: Nitric oxide; NOS: Nitric oxide synthase; PLA: Placebo; N+C: Nitrate + citrulline; BP: Blood pressure; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; MBP: Mean blood pressure; PWV: Pulse wave velocity; NIRS: Near infrared spectroscopy; TSI: Tissu saturation index; MVC: Maximal voluntary contraction; HbO2: Oxyhaemoglobin; HbTot: Total haemoglobin; HHb: Deoxyhaemoglobin.