Effects of systemic versus local hypoxia on post-activation performance enhancement in well-trained field hockey players

Abstract

Background: The aim of this study was to investigate the effect of systemic or local hypoxia on the time course of post-activation performance enhancement (PAPE). Methods: Fourteen well-trained field hockey players (19.1 ± 1.2 years; 75.4 ± 9.3 kg) (n=14; 4 females and 10 males) were randomly given five different priming conditions: HYP (plyometrics in hypoxia), BFR (plyometrics with blood flow restriction), NORM (plyometrics in normoxia), PLChyp (plyometrics during sham hypoxia) and PLCbfr (plyometrics during sham BFR). The conditioning activity (CA) consisted of 1x5 drop-jumps (DJ), 1x5 countermovement-jumps and, 1x5 single-leg horizontal jumps (on both legs). Hypoxia was conducted under normobaric conditions with SpO2 clamped to 87% via a hypoxic generator. BFR was applied with a cuff positioned around the upper thighs with a pressure set to 50% of predicted individual arterial occlusion pressure (AOP). To test the effects of these interventions on PAPE, DJ was measured at baseline and at 3, 6, 9, 12, 15 and 18 min after the CA without the cuffs or mask. Results: DJ-height (the smallest worthwhile effect, SWE = 0.88cm) and flight-time (SWE = 7.07ms) at 18th min (32.3 ± 5.9 cm; 511.5 ± 46.78 ms) was significantly higher than baseline (30.0 ± 4.4 cm, p= 0.041; 493.1 ± 35.9 ms, p=0.049) after HYP. BFR improved jump height (SWE = 0.93cm) and flight-time (SWE = 7.65ms) at the 3rd min (31.7 ± 5.0 cm; 507.2 ± 39.6 ms) compared to baseline (30.2 ± 4.7 cm, p=0.01; 494.6 ± 38.4 ms, p=0.01) (p<0.05). There was no significant improvement in DJ performance throughout the recovery period for the NORM or placebo conditions (p>0.05). Conclusions: Jump performance improvement after plyometric CA appeared early with BFR and late with systemic hypoxia. Such large differences in PAPE timing are important aspects to consider when using such PAPE methods