Augmented Anabolic Responses after 8-wk Cycling with Blood Flow Restriction

Med Sci Sports Exerc. 2019 Jan;51(1):84-93. doi: 10.1249/MSS.0000000000001755.

Abstract

Introduction: Low-intensity endurance training (ET) performed with blood flow restriction (BFR) can improve muscle strength, cross-sectional area (CSA) and cardiorespiratory capacity. Whether muscle strength and CSA as well as cardiorespiratory capacity (i.e., V˙O2max) and underlying molecular processes regulating such respective muscle adaptations are comparable to resistance and ET is unknown.

Purpose: To determine the respective chronic (i.e., 8 wk) functional, morphological, and molecular responses of ET-BFR training compared with conventional, unrestricted resistance training (RT) and ET.

Methods: Thirty healthy young men were randomly assigned to one of three experimental groups: ET-BFR (n = 10, 4 d·wk, 30-min cycling at 40% of V˙O2max), RT (n = 10, 4 d·wk, 4 sets of 10 repetitions leg press at 70% of one repetition maximum with 60 s rest) or ET (n = 10, 4 d·wk, 30-min cycling at 70% of V˙O2max) for 8 wk. Measures of quadriceps CSA, leg press one repetition maximum, and V˙O2max as well as muscle biopsies were obtained before and after intervention.

Results: Both RT and ET-BFR increased muscle strength and hypertrophy responses. ET-BFR also increased V˙O2max, total cytochrome c oxidase subunit 4 isoform 1 abundance and vascular endothelial growth factor mRNA abundance despite the lower work load compared to ET.

Conclusions: Eight weeks of ET-BFR can increase muscle strength and induce similar muscle hypertrophy responses to RT while V˙O2max responses also increased postintervention even with a significantly lower work load compared with ET. Our findings provide new insight to some of the molecular mechanisms mediating adaptation responses with ET-BFR and the potential for this training protocol to improve muscle and cardiorespiratory capacity.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Bicycling / physiology*
  • Biopsy
  • Cardiorespiratory Fitness / physiology*
  • Electron Transport Complex IV / metabolism
  • Humans
  • Male
  • Muscle Strength / physiology*
  • Oxygen Consumption
  • Physical Endurance / physiology*
  • Quadriceps Muscle / anatomy & histology
  • Quadriceps Muscle / blood supply*
  • Quadriceps Muscle / diagnostic imaging
  • Quadriceps Muscle / physiology
  • RNA, Messenger / metabolism
  • Regional Blood Flow* / physiology
  • Resistance Training / methods*
  • Ultrasonography
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • RNA, Messenger
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • COX4I1 protein, human
  • Electron Transport Complex IV