Thai traditional massage treatment based on original Thai traditional massage at Wat Po was use in this study. The participants will be assigned to receive one time of Thai traditional massage one time. Thai traditional massage techniques consists of petrissage, friction, and passive stretching on head, neck, shoulders, arms, back and legs for 60 minutes.

- Cerebrovascular reactivity or cerebral CO2 reactivity test will be assessed using the ultrasound equipment (CX50, Philips, USA). Blood flow velocity (BFV) of the middle cerebral artery (MCA) will be measured during normocapnic, hypocapnic, and hypercapnic states. Subjects will be asked to wear nose clips and breathe only through a mouthpiece. Baseline (3 minutes) recordings will be taken during spontaneous breathing of room air and then subjects underwent 1 minute of maximal voluntary hyperventilation with a duty cycle of 1 second. The MCA-BFV will be recorded during the last 20 seconds of hyperventilation. After that, subjects will be asked to breathe air containing a mixture of 5 % CO2 and 21 % O2 balanced with nitrogen spontaneously for 3 minutes and the MCA-BFV will be recorded during the last minute of hypercapnia.

- Serum cortisol will be measured with cortisol EIA kit (Enzo Life Science, Switzerland).