Accelerometer-Measured Physical Activity in Children and Adolescents at Altitudes over 3500 Meters: A Cross-Sectional Study in Tibet.

There is a scarcity of studies on the physical activity (PA) of children and adolescents who live at high altitudes. This study aimed to objectively assess PA of children and adolescents living in the Tibet at altitudes over 3500 m and to examine its difference by ethnicity, gender, age/grade, and body weight status groups. A sample of 397 students aged 9⁻18 years were recruited from 7 schools in Lhasa, Tibet. PA was measured using accelerometers (ActiGraph GT3X) for seven consecutive days and moderate to vigorous PA (MVPA) was identified using the Evenson (2008) cut-points. Participant MVPA was 62.3 min/day, with 65.5 min/day during weekdays and 54.1 min/day on weekends. Indigenous Tibetans were more active than Hans, and boys had more MVPA than girls. Age had a significantly weak negative correlation with MVPA. There was no significant difference in MVPA between the non-overweight and overweight/obese groups. Overall, only 9.1% (13.8% in boys and 4.5% in girls) accumulated at least 60 min of MVPA per day. Compared to their counterparts in other regions, the daily MVPA of children and adolescents living on the Tibetan Plateau at altitudes over 3500 m was relatively high. However, the proportion of meeting the WHO's PA recommendations was extremely low.