Effects Of Lemongrass Essential Oil Fragrance Inhalation And Artificial Carbonated Spring Water Bath On Muscle Soreness

Previous research has reported that high-concentration artificial CO2-water baths (CO2 ≥ 1000 ppm) can suppress autonomic nervous system activity and promote recovery from fatigue (Yamamoto, N. et al., 2017). Additionally, the olfactory stimulation from aromatherapy has been shown to exert both stimulating and calming effects (Takenoya, F. et al., 2018). PURPOSE: The purpose of this study was to examine the effects of inhaling lemongrass essential oil fragrance and bathing in CO2-water on muscle soreness. METHODS: Six healthy male college students participated in this study. The subjects were randomly divided into an aroma group and a control group, and a crossover design was applied. The aroma group received three sprays of 1% lemongrass essential oil (Cymbopogon flexosus, containing 39.66% geraniol, 31.83% neral, and 6.93% geraniol) applied to the inside of a non-woven mask, which they wore during the experiment. Subjects performed 150 calf raises, with perceived exertion recorded every 2 minutes using the Borg CR10 scale. After the calf raises, participants immersed their lower legs (up to below the knee) in CO2-water at 35 °C for 10 minutes. Subjective thermal sensation (TS) during the lower leg bath was recorded every two minutes. General fatigue was assessed using a Visual Analogue Scale (VAS) before exercise, after exercise, and after the lower leg bath. Muscle soreness was measured using the Talag scale daily for 7 days following the experiment. Data from the aroma group and the control group were compared using a paired Student’s t-test, with the significance level set at p < 0.05. RESULTS: CR10 tended to be lower in the aroma group than in the control group during the latter half of the calf raises. VAS scores post-exercise also tended to be lower in the aroma group. VAS scores post-CO2-water bath were lower than those recorded immediately post-exercise, indicating rapid recovery. Muscle soreness in the aroma group was lower than in the control group throughout the first week following exercise. CONCLUSIONS: In this study, the inhalation of lemongrass essential oil fragrance appeared to modify perceived exercise intensity. Additionally, muscle soreness was consistently lower in the aroma group. Thus, the combination of aromatherapy and CO2-water lower leg baths may enhance recovery and improve work efficiency.