The effects of intermittent vs. continuous blood-flow restriction methods combined with acute countermovement jump exercise on post-activation potentiation

Abstract Objectives To investigate the acute effects of two pre-activation protocols combining blood-flow restriction (BFR) with acute countermovement jump (CMJ) exercise on post-activation potentiation (PAP), to clarify their time-course characteristics and identify the optimal potentiation window, and to elucidate the underlying physiological mechanisms regarding the balance between neuromuscular potentiation and metabolic fatigue induced by different occlusion patterns. Materials and methods Eighteen healthy male track-and-field athletes specializing in sprint and jump events participated in this study, which utilized a randomized, crossover, repeated-measures design. Kinetic data were collected using a Kistler 3D force plate at baseline and at 0, 4, 8, 12, and 16 min post-stimulus following two distinct protocols executed at 50% arterial occlusion pressure: (1) a continuous protocol, involving one set of five CMJs with BFR maintained during 60-s rest intervals; and (2) an intermittent protocol, involving one set of five CMJs with BFR released during rest intervals. The PAP effect was evaluated based on jump height, peak power, peak vertical ground reaction force (vGRF), and the average rate of force development (RFD). Results Two-way repeated-measures ANOVA revealed significant protocol × time interaction effects for all kinetic variables ( P = 0.001; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msubsup> <mml:mi>η</mml:mi> <mml:mi>p</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> </mml:math> = 0.73–0.81). Compared to the continuous protocol, the intermittent protocol yielded a significantly higher main effect for jump height (mean difference: 0.14 m, 95% CI: 0.13 to 0.16 m; P = 0.001; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msubsup> <mml:mi>η</mml:mi> <mml:mi>p</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> </mml:math> = 0.79) and peak power (mean difference: 12.68 W·kg −1 , 95% CI: 12.16 to 13.08 W·kg −1 ; P = 0.001; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msubsup> <mml:mi>η</mml:mi> <mml:mi>p</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> </mml:math> = 0.76). In the continuous protocol, all kinetic parameters across the 0 to 16-min time points were significantly reduced relative to baseline ( P &lt; 0.05; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msubsup> <mml:mi>η</mml:mi> <mml:mi>p</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> </mml:math> = 0.72–0.75), demonstrating immediate and sustained performance inhibition. Conversely, jump height, peak power, peak VGRF, and average RFD in the intermittent protocol were significantly increased at 0, 4, and 8 min compared to baseline values ( P &lt; 0.05; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msubsup> <mml:mi>η</mml:mi> <mml:mi>p</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> </mml:math> = 0.65–0.77), with peak enhancements manifesting between 4 and 8 min before returning to baseline at 12 min ( P &lt; 0.05). Conclusion The results indicate that the acute intermittent BFR pre-activation protocol successfully induces post-activation potentiation, effectively enhancing CMJ height and explosive power. Conversely, the continuous protocol fails to elicit PAP and instead exerts an acute inhibitory effect due to prolonged occlusion and accumulated fatigue. The optimal temporal window to exploit the PAP effect induced by the intermittent protocol is within 8 min post-stimulus.