Acute Effects of Continuous and Intermittent Blood Flow Restriction on Movement Velocity During Bench Press Exercise Against Different Loads.

Michal Wilk,Mariola Gepfert,Adam Zajac,Gregory C Bogdanis,Michal Krzysztofik,Petr Stastny

doi:10.3389/fphys.2020.569915

Abstract

This study evaluated the effects of continuous and intermittent blood flow restriction (BFR) with 70% of full arterial occlusion pressure on bar velocity during the bench press exercise against a wide range of resistive loads. Eleven strength-trained males (age: 23.5 ± 1.4 years; resistance training experience: 2.8 ± 0.8 years, maximal bench press strength – 1RM = 101.8 ± 13.9 kg; body mass = 79.8 ± 10.4 kg), performed three different testing protocols in random and counterbalanced order: without BFR (NO-BFR); intermittent BFR (I-BFR) and continuous BFR (C-BFR). During each experimental session, subjects performed eight sets of two repetitions each, with increasing loads from 20 to 90% 1RM (10% steps), and 3 min rest between each set. In the C-BFR condition occlusion was kept throughout the trial, while in the I-BFR, occlusion was released during each 3 min rest interval. Peak bar velocity (PV) during the bench press exercise was higher by 12–17% in both I-BFR and C-BFR compared with NO-BFR only at the loads of 20, 30, 40, and 50% 1RM (p < 0.001), while performance at higher loads remained unchanged. Mean bar velocity (MV) was unaffected by occlusion (p = 0.342). These results indicate that BFR during bench press exercise increases PV and this may be used as an enhanced stimulus during explosive resistance training. At higher workloads, bench press performance was not negatively affected by BFR, indicating that the benefits of exercise under occlusion can be obtained while explosive performance is not impaired.

Highlights

Athletes as well as recreationally trained individuals are increasingly looking for innovative techniques and methods of resistance training to provide an additional stimulus to break through plateaus, prevent monotony and achieve various training goals (Krzysztofik et al, 2019)
The post hoc analysis revealed that Peak bar velocity (PV) was higher by 12–17% in both I-blood flow restriction (BFR) and continuous BFR (C-BFR) compared with NO-BFR at the loads of 20, 30, 40, and 50% 1RM (Table 1 and Figure 2)
No differences were found between the intermittent BFR (I-BFR) and C-BFR conditions at any load

Summary

Introduction

Athletes as well as recreationally trained individuals are increasingly looking for innovative techniques and methods of resistance training to provide an additional stimulus to break through plateaus, prevent monotony and achieve various training goals (Krzysztofik et al, 2019). Effects of Occlusion on Movement Velocity as blood flow restriction (BFR), has been used as a complementary training modality, aiming to further increase muscle mass and improve strength (Wilk et al, 2018). Individual limb characteristics, as well as the width, length, shape and material of the cuffs determine the level of applied pressure and as a consequence, modify post-exercise adaptive responses to BFR training (Loenneke et al, 2012b, 2015; Jessee et al, 2016; Rawska et al, 2019; Wilk et al, 2020e). Wilk et al (2020f) speculated that mechanical work generated by the cuff, in addition to other factors, can potentially augment bar velocity and power output during resistance exercise under BFR. The BFR cuff is a passive element, but during exercise, the strain of the material and the deformation of the cuff may store and return elastic energy, which could affect power output and bar velocity compared to standard conditions (Wilk et al, 2020f)

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