No effect of acute and chronic dietary nitrate supplementation on muscle oxygen consumption-recovery following exercise

AIM: The purpose of this study was to investigate the effect of acute and chronic ingestion of BR on mVO2-recovery of the vastus lateralis following exercise. METHOD: Nine healthy recreationally active men participated in a double-blind, placebo control, cross over design study, and ingested either 2x70 ml BR (2 x 450-500 mg nitrate) or PL (2 x 0.7 – 2.52 mg nitrate) per day for six days. MuscleVO2-recovery was measured using near infrared spectroscopy (NIRS) on vastus lateralis and rapid repeated occlusions on the right thigh immediately after cycling bouts on LI- and HI-intensity. Muscle-VO2 values were fit to a mono-exponential curve in order to calculate a time-constant and look for changes between BR and PL. RESULTS: No effect was found on mVO2-recovery following a seven minute cycling bout on LI after acute and chronic ingestion of BR. No effect was found on BP, and on pVO2 and HR from end-exercise, after acute and chronic supplementation. Discussion: No analysis on mVO2-recovery after cycling on HI were done in this study. This was due to an unforeseen prolonged elevation of mVO2-values, not seen on LI, making it difficult to fit a mono exponential curve and calculate a TC. Further research is necessary to investigate mVO2-recovery on higher intensity whole body exercise. Effect of BR on mVO2-recovery might not be expected due to no effect found on pVO2, BP and HR. This study is one of the first investigate mVO2-recovery following a whole body exercise, the effect of BR is uncertain at the time