The attraction of high-altitude (HA) destinations, i.e. elevation of ≥2500 m above sea level (ASL), has significantly increased due to tourism and work purposes. Over 100 million individuals worldwide travel to HA regions annually [1]. In China, ∼51 million people travelled to the Qinghai-Tibet Plateau (average elevation >4000 m ASL) in 2017 [2]. The HA environment is predominantly characterized by hypobaric hypoxia, along with low temperatures and high ultraviolet radiation [3]. Various studies have investigated acute mountain sicknesses (AMS) and its pathophysiological mechanisms [4,5]; however, it remains largely unknown whether these acute responses could attenuate and acclimatize following prolonged exposure to HA environments. Furthermore, de-acclimatization is a reversal of HA physiological adaptations at sea level (SL), posing potential health risks [6]. It is essential to understand the acclimatization to HA and recovery after descent, as well as the underlying biological mechanisms, to protect individuals travelling to HA for extended periods.
