Beetroot Juice Increases Human Muscle Force without Changing Ca2+-Handling Proteins

Jamie Whitfield*, Daniel Gamu, George J. F. Heigenhauser, Luc J. C. Van Loon, Lawrence L. Spriet, A. Russell Tupling, Graham P. Holloway

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Purpose: This study aimed to examine the effects of 7 d of beetroot juice (BRJ) supplementation on SkM contractile characteristics and function. Methods: Recreationally active males (n = 8) underwent transcutaneous electrical muscle stimulation of the vastus lateralis for the evaluation of contractile characteristics before and after 7 d of BRJ supplementation (280 mLIdj1, similar to 26 mmol NO3-). An additional group of individuals (n = 8) followed the same supplementation protocol but underwent SkM biopsies pre and post-supplementation for the determination of proteins associated with calcium handling via Western blotting, and the ratio of reduced/oxidized glutathione (GSH: GSSG), an indicator of cellular redox state, via high-performance liquid chromatography (HPLC). Results: After supplementation, there was no change in maximal voluntary force production (602 +/- 50 vs 596 +/- 56 N) or electrically induced tetanic contractions. By contrast, force production was increased at 10 Hz electrical stimulation (41.1% +/- 2.3% vs 37.6% +/- 2.4% of peak force, P

Original languageEnglish
Pages (from-to)2016-2024
Number of pages9
JournalMedicine and Science in Sports and Exercise
Volume49
Issue number10
DOIs
Publication statusPublished - Oct 2017

Keywords

  • NITRATE
  • NITRITE
  • NITRIC OXIDE
  • EXCITATION-CONTRACTION COUPLING
  • MAXIMUM VOLUNTARY CONTRACTION
  • FORCE-FREQUENCY RELATIONSHIP
  • DIETARY NITRATE SUPPLEMENTATION
  • HUMAN SKELETAL-MUSCLE
  • TIME-TRIAL PERFORMANCE
  • REACTIVE OXYGEN
  • MITOCHONDRIAL EFFICIENCY
  • SARCOPLASMIC-RETICULUM
  • CONTRACTILE PROPERTIES
  • VASTUS LATERALIS
  • BLOOD-PRESSURE
  • NITRIC-OXIDE

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