Author(s): WADA, T.1, HIRANO, T.1, KASHIWAGI, Y.2, KAWAKAMI, Y.3, MASHIKO, K.4, TAKENOYA, F.5, YAMAMOTO, N.6, Institution: KOKUSHIKAN UNIVERSITY, Country: JAPAN, Abstract-ID: 1487

INTRODUCTION:
Aromatherapy is a therapy that uses essential oils containing aromatic components extracted from plants to achieve a better state of health, and its effects on physical and mental relaxation and stress relief have also been reported. Sleeping in low-pressure environments at altitudes of 1,500 m and 2,000 m has been shown to shorten slow-wave sleep time and reduce sleep quality. It was clarified that there is a risk of inducing sleep disorders and lowering the quality of sleep while staying at high altitude. In addition, exposure to periodic hypobaric normoxia environment (PHNE) increases post-exercise VO2 and respiratory quotient (R), and has been shown to improve ventilation efficiency and promote lipid metabolism. The purpose of this study was to investigate the recovery effects of aromatherapy aromas (two types) while exposed to a cyclical low-pressure hypoxic environment after exercise.
METHODS:
The subjects were 12 healthy college students (6 males and 6 females). Before the experiment, the content was fully explained and consent was obtained from the subjects. The subjects performed 15 minutes of exercise before the test. After the exercise, they entered a periodic hypobaric normoxia environment for 50 minutes and were compared under three conditions: lavender scented, yuzu scented, and no scented conditions. Subjects were exposed to PHNE room (NR-100E-3, Shinmei-room Inc., Japan) for 50 minutes (PHNE). EEG measurement (EEG sensor ZA-X, Proassist, Japan) was performed during PHNE condition, and the EEG was analyzed. In addition, Heart rate, RPE and Visual Analog Scale (VAS) were measured before and after PHNE exposure. Statistical evaluation of the data was done by paired student’s t-test. Significance level was set at the p < 0.05.
RESULTS:
Post-exercise heart rate was 117.3 bpm, about 60%HRmax. In post-exercise recovery, lavender and yuzu scents were 10 beats lower than controls (no significant difference). It was suggested that the aromatics may help the heart rate recover more quickly. RPE during exercise showed 15 in all three conditions. Recovery under PHNE was significantly reduced in yuzu aroma compared to controls(10.7 vs 7.7, p<0.05). Visual Analog Scale tended to be higher for yuzu aroma. EEG results showed no difference in relaxation between controls and aromas. In EEG measurements, there were no significant differences in beta waves between unscented and lavender, or lavender and yuzu, but there were significant differences between scented and unscented and yuzu(p<0.05).
CONCLUSION:
EEG measurements showed no significant difference in alpha waves among the three conditions, but beta waves were significantly lower in the yuzu aroma condition than in the no aroma condition. Since β waves indicate the active state of the brain, it was hypothesized that the yuzu aroma under cyclic hypobaric hypoxia suppressed β waves and had a restorative effect on the brain.