Table 3.

Self-reported weekly physical activity and sedentary behavior by time period, sibling order, and gender

	Older sibling		Younger sibling
	Brother (n = 42)	Sister (n = 45)	Brother (n = 44)	Sister (n = 43)
Active minutes, mean (std)
Summer	1256.1 (724.0)	895.0 (506.7)	1546.4 (1055.6)	848.0 (697.8)
Fall	1086.6 (527.9)	777.4 (568.9)	1086.9 (749.7)	726.9 (541.5)
Δ	−169.5 (847.6)	−117.6 (835.5)	−459.6 (1075.2)	− 121.1 (827.9)
P for change	0.20	0.35	0.01	0.34
MVPA MET-minutes, mean (std)
Summer	6570.1 (3914.0)	4405.1 (3213.3)	8092.5 (5847.2)	4402.8 (4018.3)
Fall	6217.7 (3073.2)	3864.1 (3114.8)	5830.8 (3897.3)	3795.1 (2956.4)
Δ	− 352.4 (4727.5)	−541.0 (4558.9)	−2261.7 (5981.0)	− 607.8 (4628.1)
P for change	0.63	0.43	0.02	0.39
Sitting minutes, mean (std)
Summer	1325.0 (1043.1)	1168.8 (701.9)	1450.0 (1535.8)	1285.2 (1577.7)
Fall	1368.6 (1043.3)	987.9 (585.7)	1138.9 (682.6)	1203.5 (732.3)
Δ	43.6 (1090.2)	− 180.9 (938.8)	−311.1 (1756.0)	−81.7 (1682.4)
P for change	0.80	0.20	0.25	0.75
Screen time minutes, mean (std)
Summer	1040.0 (859.6)	893.2 (652.0)	1048.0 (779.7)	828.4 (676.1)
Fall	959.3 (871.0)	543.9 (337.3)	641.0 (419.1)	759.0 (598.2)
Δ	−80.7 (919.2)	− 358.3 (752.6)	− 407.0 (891.8)	−69.4 (791.3)
P for change	0.57	< 0.001	0.004	0.57

Notes: Active minutes were defined as a 7-day total of moderate and vigorous physical activities (MVPA). The Compendium of Metabolic Equivalents (MET) for children was used to calculate MVPA MET-minutes, with moderate physical activity defined as 3–6 metabolic equivalents and vigorous physical activity defined as > 6.0 metabolic equivalents. Sitting minutes were defined as a 7-day total of sedentary activities such as homework or television viewing, and screen time minutes were a subset of sitting minutes that involved the use of media like television viewing or texting