This study investigated the correlation between olfactory threshold levels and baseline physical performance, and examined the immediate effects of olfactory stimulation on motor function in healthy adults. Thirty healthy adults participated in this s...
This study investigated the correlation between olfactory threshold levels and baseline physical performance, and examined the immediate effects of olfactory stimulation on motor function in healthy adults. Thirty healthy adults participated in this study. Olfactory thresholds were measured using a self-developed test kit based on the Sniffin' Sticks protocol with phenylethyl alcohol (PEA), and participants were classified into a high-sensitivity group (HSG, n=15) and a low-sensitivity group (LSG, n=15) based on the median threshold score. Physical performance was assessed using OpenCap, BlazePod, My Jump Lab, and Kinovea. No significant correlations were found between olfactory threshold levels and baseline physical performance measures. However, PEA olfactory stimulation significantly improved all physical performance measures including static balance, reaction speed, agility, vertical jump height, lower limb power, and ground contact time (p〈0.01). To examine whether the effects of olfactory stimulation differed between groups, two-way repeated measures ANOVA was conducted comparing HSG and LSG. Significant group × time interaction effects were found in reaction speed, agility, ground contact time, and ankle joint angle variability (p〈0.05), with HSG demonstrating significantly greater improvements than LSG. No significant interaction effects were observed for pelvic displacement variability, vertical jump height, or lower limb power. These findings suggest that olfactory stimulation with PEA can immediately enhance physical performance, possibly mediated by modulation of the olfactory-cerebellar network and limbic-prefrontal pathway. However, as direct neural measures (e.g., EEG, fMRI) were not obtained, the proposed mechanisms remain inferential and require further neurophysiological verification. Olfactory sensitivity may serve as a moderating variable influencing the magnitude of response to olfactory stimulation. These results provide foundational evidence for the application of olfactory stimulation as a non-pharmacological intervention in sports science and rehabilitation medicine.