Qian Deng: West China School of Public Health, West China Fourth Hospital, Sichuan University, Chengdu, China.
Jianzhong Yin: School of Public Health, Kunming Medical University, Kunming, China.
Jie Peng: West China School of Public Health, West China Fourth Hospital, Sichuan University, Chengdu, China.
Zierdi Yeerkenaili: West China School of Public Health, West China Fourth Hospital, Sichuan University, Chengdu, China.
Xianlan Li: West China School of Public Health, West China Fourth Hospital, Sichuan University, Chengdu, China.
Ziyun Wang: School of Public Health, The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang, China.
Deji Quzong: School of Medicine, Tibet University, Lhasa, China.
Xianbin Ding: Chongqing Municipal Center for Disease Control and Prevention, Yuzhong, China.
Jinjie Xia: Chengdu Center for Disease Control and Prevention, Chengdu, China.
Yufei Wang: School of Public Health, Georgia State University, Atlanta, GA, USA.
Xing Zhao: West China School of Public Health, West China Fourth Hospital, Sichuan University, Chengdu, China.
Junmin Zhou: West China School of Public Health, West China Fourth Hospital, Sichuan University, Chengdu, China. ORCID
Previous studies speculated that physical activity (PA) at high altitude represents greater actual exercise than when performed at lower altitude. Efforts are needed to validate or reject such speculation. This study explored the relationships between PA changes and weight/body mass index changes in low and high altitudes. According to a previous study and the altitude distribution of our participants, we classified the participants into low altitude (<2500 m) and high altitude (���2500 m). The relationships between changes in PA and weight/body mass index were assessed through multivariable linear regression. Furthermore, the stratified analyses were conducted to detect whether there was heterogeneity in relationships between PA changes and weight/body mass index changes across low altitude and high altitude. A total of 10���000 individuals were included (9122 in low altitude, 878 in high altitude). PA increases, per MET-h/d, were inversely associated with weight changes in low altitude with a mean change of -0.009 kg (95% CI [-0.015, -0.002] kg), and in high altitude with a mean change of -0.032 kg (95% CI [-0.056, -0.009] kg). The inverse relationship between changes in PA and weight was significantly modified by altitude ( = .016), and it was stronger among participants residing at high altitude. It suggests that future guidelines and interventions should differentiate populations in low and high altitudes. Specifically, PA recommendations for people living at high altitude should be lower than those for people living at low altitude.
