Cycling with blood flow restriction improves performance and muscle K+ regulation and alters the effect of anti‐oxidant infusion in humans

Document Type

Journal Article

Publication Title

The Journal of Physiology

ISSN

1469-7793

Volume

597

Issue

9

First Page

2421

Last Page

2444

PubMed ID

30843602

Publisher

John Wiley and Sons, Ltd

School

School of Medical and Health Sciences

RAS ID

31113

Funders

Funding information available at: https://doi.org/10.1113/JP277657

Comments

Christiansen, D., Eibye, K. H., Rasmussen, V., Voldbye, H. M., Thomassen, M., Nyberg, M., ... Bangsbo, J. (2019). Cycling with blood flow restriction improves performance and muscle K+ regulation and alters the effect of antioxidant infusion in humans. The Journal of physiology, 597(9), 2421-2444. Available here

Abstract

Key points

  • Training with blood flow restriction (BFR) is a well‐recognized strategy for promoting muscle hypertrophy and strength. However, its potential to enhance muscle function during sustained, intense exercise remains largely unexplored.
  • In the present study, we report that interval training with BFR augments improvements in performance and reduces net K+ release from contracting muscles during high‐intensity exercise in active men.
  • A better K+ regulation after BFR‐training is associated with an elevated blood flow to exercising muscles and altered muscle anti‐oxidant function, as indicated by a higher reduced to oxidized glutathione (GSH:GSSG) ratio, compared to control, as well as an increased thigh net K+ release during intense exercise with concomitant anti‐oxidant infusion.
  • Training with BFR also invoked fibre type‐specific adaptations in the abundance of Na+,K+‐ATPase isoforms (α1, β1, phospholemman/FXYD1).
  • Thus, BFR‐training enhances performance and K+ regulation during intense exercise, which may be a result of adaptations in anti‐oxidant function, blood flow and Na+,K+‐ATPase‐isoform abundance at the fibre‐type level.

Abstract

We examined whether blood flow restriction (BFR) augments training‐induced improvements in K+ regulation and performance during intense exercise in men, and also whether these adaptations are associated with an altered muscle anti‐oxidant function, blood flow and/or with fibre type‐dependent changes in Na+,K+‐ATPase‐isoform abundance. Ten recreationally‐active men (25 ± 4 years, 49.7 ± 5.3 mL kg−1 min−1) performed 6 weeks of interval cycling, where one leg trained without BFR (control; CON‐leg) and the other trained with BFR (BFR‐leg, pressure: ∼180 mmHg). Before and after training, femoral arterial and venous K+ concentrations and artery blood flow were measured during single‐leg knee‐extensor exercise at 25% (Ex1) and 90% of thigh incremental peak power (Ex2) with i.v. infusion of N‐acetylcysteine (NAC) or placebo (saline) and a resting muscle biopsy was collected. After training, performance increased more in BFR‐leg (23%) than in CON‐leg (12%, P < 0.05), whereas K+ release during Ex2 was attenuated only from BFR‐leg (P < 0.05). The muscle GSH:GSSG ratio at rest and blood flow during exercise was higher in BFR‐leg than in CON‐leg after training (P < 0.05). After training, NAC increased resting muscle GSH concentration and thigh net K+ release during Ex2 only in BFR‐leg (P < 0.05), whereas the abundance of Na+,K+‐ATPase‐isoform α1 in type II (51%), β1 in type I (33%), and FXYD1 in type I (108%) and type II (60%) fibres was higher in BFR‐leg than in CON‐leg (P < 0.05). Thus, training with BFR elicited greater improvements in performance and reduced thigh K+ release during intense exercise, which were associated with adaptations in muscle anti‐oxidant function, blood flow and Na+, K+‐ATPase‐isoform abundance at the fibre‐type level.

DOI

10.1113/JP277657

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free_to_read

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