Effect of Physical Activity on Olfactory Acuity: A Systematic Review

Olfactory acuity, which includes detection thresholds, identification and appreciation/intensity, seems to decline with aging, obesity, and various neurological disorders. Knowing that the sense of smell influences energy intake, the interest in protecting this sense is constantly increasing. Physical activity might be a key intervention to counteract the loss of olfactory function. This systematic review aims to explore the literature on the effect of physical activity on olfactory acuity. The search strategy consisted of using index terms and keywords in MEDLINE, EMBASE, EBM Reviews - Cochrane Central Register of Controlled Trials, CINAHL, SPORTDiscus, and Web of Science search engine. Data from 17 studies that include 10 861 participants revealed that physical activity has improved olfactory thresholds, identification, and intensity. More precisely, chronic physical activity seemed to have better effects on olfactory components than acute practice. Even though this review clarified evidence about the effect of physical activity on the sense of smell, better methodological consistency is needed across studies such as standardized experimental conditions, the time of the day data are collected, and similar relative energy intake between participants to produce more robust results.