Acute neuromuscular, metabolic, and perceptual responses to low-load isokinetic exercise under varying percentages of arterial occlusion pressure.

Objective: To examine whether graded arterial occlusion pressure (AOP) during low-load isokinetic exercise differentially modulates neuromuscular activation, metabolic stress, and perceptual strain, and to identify an occlusion level that maximizes stimulus while minimizing perceived burden. Methods: Twelve healthy young men (21.3 ± 1.6 years) completed four randomized, counterbalanced sessions under 0%, 60%, 70%, and 80% AOP. During each session, isokinetic knee extension/flexion was performed at a low load under the assigned occlusion condition. Muscle activation was quantified using surface EMG and expressed as %EMGmax. Capillary blood lactate (BLa) was assessed at baseline and during recovery, and rating of perceived exertion (RPE) was recorded immediately after exercise. Results: Occlusion pressure produced a clear dose-response pattern in metabolic stress and neuromuscular demand. Both %EMGmax and BLa increased with higher AOP, with the most consistent elevations occurring at ≥70% AOP (p < 0.05). Importantly, raising occlusion from 70% to 80% AOP did not provide additional gains in %EMGmax, whereas RPE increased significantly at 80% AOP compared with 70% AOP (p < 0.05). Conclusion: Low-load isokinetic exercise performed at 70% AOP elicits robust neuromuscular and metabolic stimulation without additional gains relative to 80% AOP while imposing a substantially lower perceptual load. These findings support 70% AOP as a practical "compromise point" for acute BFRT prescription when balancing training stimulus and tolerability.