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.

Fewer and fewer people are reaching physical activity recommendations. Therefore, it seems important to make the practice of physical activity more enjoyable to increase the participation rate. Several environmental factors have been studied to see their impact on sports practice, and some studies investigated the effect of odors. This systematic review aims to provide a thorough view of the literature on the effect of different odors on physical activity. 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 19 studies that included 421 participants revealed that the odors had different results on strength, cardiovascular, precision, and postural balance tasks depending on the odors' exposition. Among results, an important distinction was made between pleasant and unpleasant odors. Therefore, pleasant odors had better results on physical activity by improving participants' feeling. Even though this review clarified evidence about the effect of odors on physical activity, better methodological consistency is needed across studies such as the odor administration method to produce more meaningful results.