Table 1

Sleep characteristics for sea-level natives and high-altitude natives

VariableSea-level natives (Australians, n=14)High-altitude natives (Bolivians, n=12)
Sleep type (mean (±SD))Sleep type (mean (±SD))
Sea level (average)High altitude (acute)High altitude (average)Sea level (average)High altitude (acute)High altitude (average)
Time in bed (h)9.2 (±0.8)8.8 (±1.0)9.1 (±0.7)7.8 (±0.6)8.0 (±0.8)8.4 (±1.1)
Sleep onset (hh:mm)23:40 (±0:47)23:57 (±0:38)00:02 (±0:46)00:24 (±0:38)00:17 (±0:31)00:21 (±0:42)
Sleep offset (hh:mm)08:25 (±0:37)08:13 (±0:45)08:28 (±0:34)07:40 (±0:23)07:50 (±0:40)08:21 (±0:68)
Total sleep time (h)7.0 (±0.5)6.1 (±0.7)6.5 (±0.7)5.7 (±0.7)5.9 (±0.9)6.4 (±1.0)
Cumulative sleep time (h)7.0 (±0.5)6.1 (±0.7)6.5 (±0.7)5.7 (±0.7)5.9 (±0.9)6.4 (±1.0)
Sleep efficiency (%)80 (±3)75 (±5)77 (±5)78 (±6)78 (±8)80 (±6)
Move and Frag Index25 (±6)30 (±8)29 (±7)24 (±8)26 (±10)24 (±8)
Subjective sleep quality3.8 (±0.7)2.8 (±0.6)3.8 (±0.6)3.9 (±0.6)4.2 (±0.4)4.3 (±0.4)
  • Measures of sleep quantity and sleep quality for the Australians and Bolivians for (1) an average sleep at near sea level (based on the last two nights at near sea level), (2) the first sleep at high altitude and (3) an average sleep at high altitude (based on the last four nights that the Bolivians collected data).