The Use of a Just Noticeable Difference Approach to Improve Perceptual Acuity Ability in Male Runners.

This article investigates the just noticeable difference (JND)—a psychophysical measure of perceptual acuity—in trained male runners at exercise intensities of 70% and 80% of their maximal oxygen uptake (VO2max). Using treadmill trials, the study quantified how small variations in physiological demand (VO2) correspond to runners' ability to perceive changes in exertion above and below these standard intensities. Results showed that the JND range narrows as physiological demand increases, with a smaller total JND magnitude at 80% VO2max compared to 70% VO2max, indicating reduced perceptual sensitivity near peak exertion. The findings suggest that understanding an athlete's JND can help coaches prescribe training intensities within a perceptual acuity range to enhance self-regulation of pace and avoid fatigue-related performance decline.