Objectives - To observe changes in sleep from baseline and during an altitude training camp in elite endurance athletes.<p> <p>Design - Prospective, observational.<p> <p>Setting - Baseline monitoring at <500 m for 2 weeks and altitude monitoring at 1800 m for 17-22 days.<p> <p>Participants - Thirty-three senior national-team endurance athletes (mean age 25.8 ± S.D. 2.8 years, 16 ...