Similar Neuromuscular and Morphological Adaptations Following Short-Term Blood Flow Restriction and Traditional Resistance Training in Young Men

Abstract Pennartz, KJ, Smith, CD, Washington, S, Gebert, R, Wolfe, A, Keller, JL, and Luera, MJ. Similar neuromuscular and morphological adaptations following short-term blood flow restriction and traditional resistance training in young men. J Strength Cond Res 39(12): 1262–1268, 2025—The purpose of this study was to evaluate changes in muscular strength and size, as well as electrical efficiency (EE), in response to either 4 weeks of low-load blood flow restriction (BFR) or low-load non-BFR resistance training in young, healthy men. Twenty-one untrained men completed a 4-week randomized, between-group parallel training intervention consisting of 4 sets (1 × 30, 3 × 15) of repeated isokinetic (60°·s −1 ) ankle dorsiflexions at 30% of peak torque with BFR or without BFR at 40% arterial occlusion pressure. Muscle cross-sectional area (mCSA), isokinetic and isometric strength, and EE were assessed pretraining and posttraining. A p -value ≤0.05 was considered significant. Separate mixed factorial ANOVAs (group × time) were used to test mean differences. Muscle strength did not change in the BFR or non-BFR group ( p > 0.05; = 0.06); however, mCSA increased to a similar extent in both groups ( p < 0.01; = 0.72). Neither training approach induced a change in EE ( p > 0.05; = 0.001). Based on these results, low-load resistance training with BFR may not lead to unique or enhanced muscular adaptations, especially in the tibialis anterior, possibly due to musculotendinous mechanical properties and other factors. Furthermore, BFR may reverse the expected order of resistance training-induced adaptations (i.e., neural then hypertrophy) by accelerating metabolite buildup, as evidenced by the increase in mCSA without increases in strength or neuromuscular adaptations. Strength and conditioning professionals seeking to improve dynamic ankle dorsiflexion in young, healthy men may not find additional benefits when applying BFR in a short-term intervention.