体育活动（PA）可能会改变癌症后晚期影响的风险。我们旨在研究一个大型的国际样本中青少年儿童癌症幸存者的体育活动水平和久坐时间（ST），并与社会人口学和癌症相关因素进行比较，并将体育活动水平和久坐时间与参考队列进行比较。对于任何癌症诊断过且癌症治疗已完成≥1年的9至16岁幼儿癌症幸存者，都有资格参加多中心儿童癌症幸存者体育活动研究。体育活动和久坐时间通过ActiGraph GT3X+加速计进行测量。我们进行线性回归分析以评估与中等至高强度体育活动（MVPA）和久坐时间相关的因素，并使用聚合数据的直接t检验将432名幸存者的总体PA、MVPA和ST的边际平均值与性别和年龄分层的参考组（两年间隔）进行比较。在幸存者中，有34%满足世界卫生组织的建议，平均每天进行≥60分钟的中等至高强度体育活动，并且他们的久坐时间为8.7小时。女性、年龄较大、超重、中枢神经系统肿瘤的幸存者或有复发经历的幸存者与较低的MVPA和/或较高的ST有关。一般来说，与参考组相比，男性幸存者在中等至高强度体育活动上花费的时间较短，而女性幸存者的水平类似。在几乎所有年龄组中，男性和女性幸存者的久坐时间都比参考组高。这个大样本的青少年儿童癌症幸存者中体育活动低和久坐时间高的情况令人担忧。综合而言，我们的结果呼吁在儿童癌症的后续护理中有针对性地介入这两个方面。

Physical activity (PA) may modify risks of late effects after cancer. We aimed to examine levels of PA and sedentary time (ST) in a large, international sample of adolescent childhood cancer survivors in relation to sociodemographic and cancer-related factors and compare levels of PA and ST to reference cohorts.Survivors from any cancer diagnosis who had completed cancer treatment ≥1 year ago, aged 9 to 16 years, were eligible for the multicenter Physical Activity in Childhood Cancer Survivors study. PA and ST were measured by ActiGraph GT3X+ accelerometers. We performed linear regression analyses to assess factors associated with moderate-to-vigorous PA (MVPA) and ST, and compared marginal means of total PA, MVPA, and ST in 432 survivors to sex- and age-stratified references (2-year intervals) using immediate t-tests for aggregated data.Among survivors, 34% fulfilled the World Health Organization's PA recommendation of ≥60 min of daily MVPA on average and their ST was 8.7 hours per day. Being female, older, overweight, a survivor of central nervous system tumor, or having experienced relapse were associated with lower MVPA and/or higher ST. Generally, male survivors spent less time in MVPA compared with references, whereas female survivors had similar levels. Both male and female survivors had higher ST than references in nearly all age groups.The low PA and high ST in this large sample of adolescent childhood cancer survivors is worrisome. Combined, our results call for targeted interventions addressing both PA and ST in follow-up care after childhood cancer.