Effects of Low-Load Blood-Flow Restriction Training Versus High-Load Resistance Training on Neuromuscular Performance and Neuromuscular Activation.

Low-load blood-flow restriction (BFR) training is a potential alternative to high-load (HL) resistance training, especially when mechanical stress must be minimized. However, its effects on neuromuscular activation remain unclear. This randomized controlled trial compared changes in voluntary activation (VA) and neuromuscular performance following 8 weeks of BFR versus HL knee extensor training and examined the effects of a subsequent 2-week HL phase in both groups. Thirty-seven healthy adults (37-59 years, 22 female) underwent progressive BFR or HL training for 8 weeks (phase 1), followed by 2 weeks of HL training on knee extensor muscles (phase 2). Outcomes included VA, maximal isometric and dynamic leg extension and leg press strength, rate of force development (RFD), and jump performance. Linear mixed models were used to analyze group*time interactions; Cohen's d effect sizes are reported. After both training phases, the BFR group showed smaller improvements than HL in VA (d = -0.31 to -0.37), maximal isometric strength (d = -0.07 to -0.27), dynamic strength (d = -0.18 to -0.75), and RFD (d = -0.48 to -0.54). Jump performance showed trivial between-group differences (d = -0.01 to -0.05). Although a subsequent 2-week HL phase improved outcomes in the BFR group, it did not fully restore neural adaptations to the level of continuous HL training. These findings underscore the essential role of mechanical loading in optimizing neuromuscular function. While BFR may serve as a useful preparatory method in contexts where high loads are initially contraindicated, follow-up HL training is required to maximize neuromuscular adaptation. Trial Registration: This study was preregistered on the Open Science Framework (DOI: 10.17605/OSF.IO/DA6SV).