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.
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.
Thirty healthy young men were randomly assigned to one of three experimental groups: ET-BFR (n = 10, 4 d·wk−1, 30-min cycling at 40% of V˙O2max), RT (n = 10, 4 d·wk−1, 4 sets of 10 repetitions leg press at 70% of one repetition maximum with 60 s rest) or ET (n = 10, 4 d·wk−1, 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.
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.
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.
1Faculty of Physical Education, University of Campinas, Campinas, BRAZIL;
2School of Physical Education and Sport, University of São Paulo, São Paulo, BRAZIL;
3MuscuLab, Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos, São Carlos, BRAZIL;
4Obesity and Comorbidities Research Center (OCRC), Institute of Biology, University of Campinas, Campinas, BRAZIL; and
5Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Melbourne, AUSTRALIA
Address for correspondence: Miguel S. Conceição, Ph.D., Faculty of Physical Education, University of Campinas Av. Érico Veríssimo, 701, Cidade Universitária “Zeferino Vaz” Barão Geraldo, Campinas, São Paulo, CEP 13083-851, Brazil; E-mail: firstname.lastname@example.org.
Submitted for publication November 2017.
Accepted for publication July 2018.
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