The primary outcomes were subjective fatigue score, assessed by VAS (which is recommended in the guideline published by the Japanese Society of Fatigue Science [22]) and CFQ [23]. The other outcomes were work efficiency, mood state (Japanese version of the Profile of Mood States 2 scale (POMS2)) [24], Ogri-Shirakawa-Azumi sleep inventory MA version (OSA-MA) [25], autonomic nerve activity, oxidative stress marker and safety.