Howe 2011.

Study characteristics
Methods	Study design: RCT Intervention period: 10 months Follow‐up period (post‐intervention): nil Differences in baseline characteristics: NR for whole intervention group Intervention group was divided into attenders (ATT) and non‐attenders (NATT), participating in ≥ 60% or < 60% of the intervention, respectively. Reliable outcomes: reported Protection against contamination: reported Unit of allocation: individual Unit of analysis: individual
Participants	N (controls baseline) = NR N (controls follow‐up) = 44 N (interventions baseline) = NR N (interventions follow‐up) = 62 N = 157 consented and N = 122 had baseline testing (intervention + control) Setting: 5 elementary/primary schools Recruitment: children in selected schools were phoned by researchers and screened for eligibility Geographic region: Georgia, USA Percentage of eligible population enrolled: 1050 = target population. 28% of these (300) were screened by phone. Unclear how selected 28% Mean age: NR. All children 8‐12 years Intervention: NR (but between 9.7 and 9.8) Control: 9.9 ± 0.2 (SE) Sex: intervention, 0% female; control, 0% female
Interventions	A 10‐month after‐school PA intervention. The daily intervention (2 h/day) consisted of skills development (25 min), vigorous PA (35 min), and strengthening/stretching (20 min) components. A healthy snack was offered during the 2‐h intervention. The intervention was conducted by trained study personnel with exercise‐related education plus 1‐2 trained classroom teachers. Participants in the control group received no intervention and were not allowed to stay for the after‐school intervention but rather instructed not to change their daily after‐school routine. PA vs control
Outcomes	Outcome measures Difficult to assess which outcomes were primary and which were secondary: Body fatness a. Height and weight measured and BMI calculated b. Waist circumference Total body composition using DEXA (fat mass, fat‐free mass, % body fat, etc) Cadiovascular fitness MVPA Process: NR
Implementation‐related factors	Theoretical basis: NR Resources for intervention implementation: NR Who delivered the intervention: reported PROGRESS categories assessed at baseline: NR PROGRESS categories analysed at outcome: NR Outcomes relating to harms/unintended effects: NR Intervention included strategies to address diversity or disadvantage: NR Economic evaluation: NR
Notes	All children were African American boys
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	No mention of method of randomisation Quote: "participants was randomized into either the intervention group (n=62) or the control group (n=44) with a ratio of three to two, respectively. In the instance of siblings, the 1st to be tested was randomized and the remaining sibling(s) was/were placed in the same group."
Allocation concealment (selection bias)	Unclear risk	NR
Blinding (performance bias and detection bias) All outcomes	Unclear risk	NR
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information, N = 157 consented and N = 122 had baseline testing (intervention + control), N = 106 randomised
Selective reporting (reporting bias)	Unclear risk	Protocol/trial registration documents were unavailable
Other bias	Low risk	None identified