The effects of transmeridian travel and altitude on sleep : preparation for football competition

International competitions require football teams to travel across multiple time zones. In some circumstances these competitions are held at altitudes of up to 3600 m. This presents football players with challenges associated with transmeridian travel and altitude exposure, which have been shown to impair sleep quantity and quality (Reilly,2009; Roach et al., 2013). Specifically, youth football players’ at altitude obtain less deep sleep and less rapid eye movement sleep (Sargent et al., 2013). Given that muscle recovery takes place during deep sleep, the reduction in deep sleep at altitude may limit athletes’ postexercise processes (Dattilo et al., 2011, Samuels, 2008). Sleep disturbances in athletes has been shown to decline with the amount of time spent at altitude, at least in the absence of jet-lag (Roach et al., 2013, Sargent et al., 2013). Yet, international competition at altitude is often accompanied by transmeridian travel, which causes a temporary misalignment between the internal body clock and the local destination time. Although transmeridian travel and altitude exposure are known to disrupt sleep, their combined effects have not been examined. To address this oversight, this study examined the longitudinal changes in the extent of sleep disruption, in response to, the combination of transmeridian travel and ascending to altitude.