“…Twelve studies measured MVPA through observational measures (e.g., SOFIT) [ 19 , 20 , 29 , 32 , 34 – 36 , 38 – 40 , 43 , 45 – 47 ], seven used accelerometers [ 24 , 25 , 28 , 33 , 37 , 41 , 44 ], five used heart rate monitors [ 19 , 20 , 22 , 23 , 26 , 31 ] and four used pedometers [ 21 , 27 , 46 , 47 ]. The majority of middle school studies assessed physical activity through observational measures ( n = 5/7).…”