Physiological and Psychophysical Dynamics in the Perceptual Acuity Ability of Male Endurance Runners

Krause, MP, Antonio, DS, Bigliassi, M, Nascimento, VB, and Haile, L. Physiological and psychophysical dynamics in the perceptual acuity ability of male endurance runners. J Strength Cond Res XX(X): 000–000, 2026—This study examined temporal responses in oxygen consumption ( o 2 ) during just-noticeable-difference (JND) determination to identify the physiological and psychophysical magnitudes of changes required for competitive male runners to perceive subtle performance differences. Fifteen well-trained male runners (age: 34.27 ± 6.91 years; BMI: 22.81 ± 2.27 kg·m −2 ; o 2 max: 60.99 ± 4.36 ml −1 ·kg −1 ·min −1 ) completed 1 maximal incremental test to determine o 2 max and 2 JND trials at 70% o 2 max and 80% o 2 max to assess their perceptual acuity ability. Each JND trial involved four 5-minute treadmill bouts separated by 5-minute rests. Subjects ran at a standard stimulus (SS) pace in bouts 1 and 3, then adjusted speeds in bouts 2 and 4 to produce a JND in exertion above or below the SS. Statistical Parametric Mapping revealed that o 2 increased rapidly in the first minute and approached a stable response after approximately the second minute. Significant within-runner differences in o 2 temporal responses were observed across exercise bouts, while between-runner variability was more evident during the initial transition phase. Time perception shortened when running below the SS, and ratings of perceived exertion increased with intensity. Speed adjustments converged on the SS by the end of the below bout. These findings highlight how runners detect and respond to subtle physiological and psychophysical cues, underscoring the importance of micro-adjustments for effective self-regulation and performance. The o 2 -JND approach provides insights into the integration of sensory-perceptual processes during exercise.