“…Results consistently showed reported decreases in PA time in children and youth, and this was demonstrated repeatedly in both longitudinal 66 , 67 , 68 , 69 , 70 , 72 , 73 , 74 , 75 , 77 and cross-sectional designs. 78 , 80 , 84 , 92 , 102 , 103 , 107 , 109 , 114 , 117 , 118 This result was echoed by those of other studies using similar constructs, including exercise time, 100 , 104 , 115 energy expenditure, 79 and MVPA. 116 , 121 , 122 , 123 However, 3 longitudinal research studies reported decreases in sports-related PA 65 , 73 , 77 but not in school and leisure-time PA, 73 habitual activity, 65 and nonorganized sports-related PA. 65 It is worth noting that although studies consistently identified overall decreases in PA, there were groups of children and youth in some studies who reported stability 125 or an increase 65 , 132 in unstructured PA. Several studies reported changes in the proportion of children and youth meeting PA guidelines.…”