Active Preconditioning With Blood Flow Restriction or/and Systemic Hypoxic Exposure Does Not Improve Repeated Sprint Cycling Performance.

Mathias R Aebi,Grégoire P Millet,Olivier Girard,Sarah J Willis,Fabio Borrani

doi:10.3389/fphys.2019.01393

Abstract

PurposeThe aim of this study was to evaluate the effects of active preconditioning techniques using blood flow restriction or/and systemic hypoxic exposure on repeated sprint cycling performance and oxygenation responses.MethodsParticipants were 17 men; 8 were cycle trained (T: 21 ± 6 h/week) and 9 were untrained but physically active (UT). Each participant completed 4 cycles of 5 min stages of cycling at 1.5 W⋅kg–1 in four conditions [Control; IPC (ischemic preconditioning) with partial blood flow restriction (60% of relative total occlusion pressure); HPC (hypoxic preconditioning) in normobaric systemic hypoxia (FIO2 13.6%); and HIPC (hypoxic and ischemic preconditioning combined)]. Following a 40 min rest period, a repeated sprint exercise (RSE: 8 × 10 s sprints; 20 s of recovery) was performed. Near-infrared spectroscopy parameters [for each sprint, change in deoxyhemoglobin (Δ[HHb]), total hemoglobin (Δ[tHb]), and tissue saturation index (ΔTSI%)] were measured.ResultsTrained participants achieved higher power outputs (+10–16%) than UT in all conditions, yet RSE performance did not differ between active preconditioning techniques in the two groups. All conditions induced similar sprint decrement scores during RSE in both T and UT (16 ± 2 vs. 23 ± 9% in CON; 17 ± 3 vs. 19 ± 6% in IPC; 18 ± 5 vs. 20 ± 10% in HPC; and 17 ± 3 vs. 21 ± 5% in HIPC, for T and UT, respectively). During the sprints, Δ[HHb] was larger after IPC than both HPC and CON in T (p < 0.001). The Δ[tHb] was greater after HPC than all other conditions in T, whereas IPC, HPC, and HIPC induced higher Δ[tHb] than CON in UT.ConclusionNone of the active preconditioning methods had an ergogenic effect on repeated sprint cycling performance, despite some specific hemodynamic responses (e.g., greater oxygen extraction and changes in blood volume), which were emphasized in the trained cyclists.

Highlights

There is renewed interest for the so-called “ischemic preconditioning” (IPC) strategy and its application in the athletic field for performance improvement (Incognito et al, 2015)
None of the active preconditioning methods had an ergogenic effect on repeated sprint cycling performance, despite some specific hemodynamic responses, which were emphasized in the trained cyclists
The present study evaluated the effectiveness of separate and combined partial blood flow restriction and systemic hypoxic exposure implemented during active preconditioning on repeated-sprint exercise performance and oxygenation responses

Summary

Introduction

There is renewed interest for the so-called “ischemic preconditioning” (IPC) strategy and its application in the athletic field for performance improvement (Incognito et al, 2015). Previous researchers have typically implemented IPC at rest in athletes via total occlusion (220 mm Hg) with 3 × 5 min occlusion-reperfusion cycles (Groot et al, 2009; Clevidence et al, 2012). Contradictory results exist regarding the effects of IPC on repeated sprint exercise (RSE) performance. Repeated sprint cycling performance has been shown to improve by 1–2% when IPC is performed at rest for 30–45 min preceding RSE (Patterson et al, 2014; Lalonde and Curnier, 2015). IPC induced similar performance outcomes as a sham during either 5 × 6 s repeated sprints (Gibson et al, 2015) or 6 × 6 s sprints and a 30 s Wingate test (Lalonde and Curnier, 2015)

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