Yudai Takarada
Effort perception-the subjective experience of how hard an action feels-arises from the integration of peripheral sensory signals, central motor inhibition, and higher order cognitive appraisal. Blood flow restriction (BFR) provides a unique context in which these interactions are amplified, revealing how the perception-action relationship can be distorted even when mechanical load is low. This review synthesizes evidence across neurophysiology, psychology, and applied exercise science to propose a hierarchical model in which effort perception is reconstructed through multilevel integration rather than determined by any single physiological source. In this framework, lower-level signals constrain but do not determine higher-level processes, while higher-level cognitive and motivational systems modulate the gain and precision of sensory information. At the peripheral level, group III/IV afferents and vascular distension sensitive receptors encode metabolic and mechanical states. At the central level, reduced excitability of the primary motor cortex (M1) and compensatory engagement of higher order motor regions reshape how these signals are processed. At the cognitive and motivational level, mental fatigue, unconscious goal priming, and arousal modulation recalibrate the reference frames through which effort is evaluated. BFR magnifies these interactions, illustrating how acute distortions of effort perception may, over repeated exposure, contribute to the recalibration of perceptual thresholds, although the mechanisms linking acute distortions to chronic adaptations remain uncertain. Rather than presenting a fully validated causal theory, this hierarchical model serves as an integrative framework that organizes existing evidence, clarifies evidence strength across levels, and generates testable predictions relevant to neuroergonomics, rehabilitation, aging and athletic performance.