# The Effect of Aromatherapy on Post-Exercise Hypotension: A Pilot Study
## 4 Discussion
A notable finding was the lack of difference in HR recovery in response to aromatherapy, despite the potential influence of aroma on ANS and thereby on the HR. Similar results have been reported in the literature. A recent study discovered no difference in HR recovery between lavender and placebo treatments at 5, 10, and 15 min during the recovery phase after exercise [34]. In addition, [PERSON] et al. also reported that exposure to lavender following exercise has no significant effect on HR recovery [35]. Unfortunately, these previous studies did not discuss these findings, and we could not find clues to draw a putative explanation for this finding. Thus, this part remains an interesting topic for future research, with a large sample size and different dosages, delivery methods, exercise modalities, etc. Lactate is produced from carbohydrate glycolysis under anaerobic conditions, and its accumulation leads to acidosis, which contributes to fatigue [12]. Thus, rapid lactate clearance is essential for quick recovery after exercise. In this pilot study, post-exercise aromatherapy did not seem to influence lactate clearance, implying that aromatherapy-induced augmentation of PEH might not be associated with metabolic effects. Although subtle evidence suggests that aromatherapy can influence the hormonal balance by stimulating the hypothalamus and pituitary glands [28; 35], the relatively small dosage and brief exposure time in this study may not significantly impact metabolic recovery. This pilot study has several limitations, particularly in its methodological approaches, to notice. First, since the study involved only young normotensive males, generalizing the results to older individuals, patients with hypertension, or even females remains uncertain [36]. Nonetheless, given the global trend of increasing prevalence of hypertension among younger populations, our results are somewhat meaningful and indicate the necessity of application to larger and more diverse populations. Second, a one-week washout interval between experiments might not be enough to completely avoid the carryover effects. Although previous studies on the effect of essential oils exhibited that a washout period of one week or even less than a week did not influence their results [19; 20], this would be different depending on the essential oil types, exposure methods, duration, timing, etc. Therefore, a longer interval needs to be considered for solid outcomes in future studies. Third, blindness to treatments might be unsecure due to the unique odor of essential oils, although the participants were not informed about inhaling materials. Thus, it is required to consider ways to address this issue in future research. Overall, our preliminary findings from this pilot study can lead to the future studies which conduct experiments to ensure clinical efficacy in large participant groups or different groups of subjects, such as hypertensives and elderlies, who need urgent help to control their BP. Future studies should explore different aromas and their comparative effects on cardiovascular and autonomic parameters with mechanistic biomarkers and autonomic measures. In addition, as long-term interventions are required to alter physiological baselines, the acute effects observed in this study limit the conclusions regarding the long-term benefits or habituation effects of exercise on BP and vascular stiffness.