摘要：We quantified the moderate-to-vigorous physical activity (MVPA, heart rate ≥140 bpm) of urban public elementary school children on school days with and schooldays without physical education (PE) class by using continuous heart rate monitoring. The heart rate of 81 students (93.8% black) in grades 3 and 5 was recorded in 15-second intervals. On the basis of 575 school-day observations (mean 7.1 days/student), students accumulated 44.4 (standard deviation [SD], 34.4) minutes of MVPA on days with PE and 30.6 (SD, 29.9) MVPA minutes on days without PE (P < .001). School policies should promote daily PE to help children in under-resourced areas achieve the recommended 60 minutes per day of MVPA.
