SUPPLEMENTAL DIGITAL CONTENT Sample size calculation
As recommended by Faul, Erdfelder, Lang, and Buchner,
1sample sizes in
CHIPMANC and JETPAC were calculated a priori using G*Power 3.1.9.4. In healthy children, a meta-analysis found a small effect of exercise with coordinative/
cognitive demands on executive function (effect size pooled for working memory
and inhibitory control: d = 0.39).
2Based on a similar meta-analysis in children
with ADHD, a moderate effect on this cognitive domain was reported (effect size
pooled for working memory and inhibitory control: d = 0.59).
3As executive
function deficits are similar between children with ADHD and those born very
preterm
4, a moderate effect of exercise on executive function was expected
among both groups due to a comparable adaptation reserve. Based on this effect
size and an estimation of a drop-out rate of 20 %, the power analysis indicated
that 56 participants were required to reach 85 % power to detect a treatment
effect within each study.
Table S1. CONSORT checklist.
Section/Topic Item
No Checklist item Page
No Title and abstract
1a Identification as a randomised trial in the title 1 1b Structured summary of trial design, methods, results, and
conclusions (for specific guidance see CONSORT for
abstracts) 2
Introduction Background
and objectives
2a Scientific background and explanation of rationale 3-5
2b Specific objectives or hypotheses 5
Methods
Trial design
3a Description of trial design (such as parallel, factorial)
including allocation ratio 7
3b Important changes to methods after trial commencement
(such as eligibility criteria), with reasons NA
Participants 4a Eligibility criteria for participants 6-7
4b Settings and locations where the data were collected 7 Interventions 5 The interventions for each group with sufficient details to
allow replication, including how and when they were actually
administered 7-8
Outcomes
6a
Completely defined pre-specified primary and secondary outcome measures, including how and when they were
assessed 7-9
6b Any changes to trial outcomes after the trial commenced,
with reasons NA
Sample size
7a How sample size was determined Supple
ment 7b When applicable, explanation of any interim analyses and
stopping guidelines NA
Randomisation:
Sequence generation
8a Method used to generate the random allocation sequence 7 8b Type of randomisation; details of any restriction (such as
blocking and block size) 7
Allocation concealment
mechanism 9
Mechanism used to implement the random allocation sequence (such as sequentially numbered containers), describing any steps taken to conceal the sequence until
interventions were assigned
7
Implemen-
tation 10 Who generated the random allocation sequence, who enrolled participants, and who assigned participants to
interventions 7
Blinding 11a
If done, who was blinded after assignment to interventions (for example, participants, care providers, those assessing
outcomes) and how 7
11b If relevant, description of the similarity of interventions 7-8 Statistical
methods
12a Statistical methods used to compare groups for primary and
secondary outcomes 10
12b Methods for additional analyses, such as subgroup analyses
and adjusted analyses 10
Results
Participant flow
13a For each group, the numbers of participants who were randomly assigned, received intended treatment, and were
analysed for the primary outcome
Figure 1, 10 13b For each group, losses and exclusions after randomisation,
together with reasons Figure 1
Recruitment 14a Dates defining the periods of recruitment and follow-up 7
14b Why the trial ended or was stopped 7
Baseline data 15 A table showing baseline demographic and clinical
characteristics for each group Table 1 Numbers
analysed 16 For each group, number of participants (denominator) included in each analysis and whether the analysis was by
original assigned groups Table 2
Outcomes and estimation
17a For each primary and secondary outcome, results for each group, and the estimated effect size and its precision (such
as 95% confidence interval)
Table S3, 10-
11 17b For binary outcomes, presentation of both absolute and
relative effect sizes is recommended NA Ancillary
analyses 18 Results of any other analyses performed, including subgroup analyses and adjusted analyses, distinguishing pre-specified
from exploratory NA
Harms 19 All important harms or unintended effects in each group (for
specific guidance see CONSORT for harms) NA Discussion
Limitations 20 Trial limitations, addressing sources of potential bias,
imprecision, and, if relevant, multiplicity of analyses 15-16 Generalisabilit
y 21 Generalisability (external validity, applicability) of the trial
findings 12,15
Interpretation 22 Interpretation consistent with results, balancing benefits and
harms, and considering other relevant evidence 12-15 Other information
Registration 23 Registration number and name of trial registry 7 Protocol 24 Where the full trial protocol can be accessed, if available NA Funding 25 Sources of funding and other support (such as supply of
drugs), role of funders 16
Table S2. Correlation between potential confounders, behavioral performance and event-related potential components.
Go RT Omissio
n ER Commis
sion ER N2 P3b P3a PWC17
0 MABC-
2
Age -0.37* -0.13 -0.04 -0.12 -0.05 0.04 0.15 0.12
Sex (0 = m /
1 = f) 0.06 -0.22* -0.32* -0.03 -0.06 0.08 -0.13 0.00
BMI -0.19* 0.07 0.09 -0.02 0.11 0.05 -0.48* -0.27*
IDS-2 0.11 0.04 -0.02 0.21* 0.08 0.08 0.11 0.12
FAS score -0.13 -0.06 0.03 -0.01 -0.05 0.13 0.14 0.17
SDQ sum
score 0.05 0.07 0.15 -0.16 0.04 -0.15 -0.13 -0.32*
Notes: * = p < 0.05; BMI = Body Mass Index; ER = Error rate; IDS-2 = Intelligence and Developmental Scales – 2, value points derived from IQ screening items (naming categories and complete matrices); FAS = Family Affluence Scale; RT = Reaction time; SDQ = Strengths and Difficulties Questionnaire
Table S3. Overview of interactions of time, group and study for cognitive performance, event-related potential components and physical fitness.
Outcome Interaction F df, error df η2
Performance
Go reaction timea Time x group 2.91 1, 104 0.027
Time x group x study 0.05 1, 104 < 0.001
Omission ERb Time x group 0.11 1, 104 < 0.001
Time x group x study 0.16 1, 104 < 0.001
Commission ERb Time x group 0.11 1, 104 < 0.001
Time x group x study 6.93* 1, 104 0.062
ERPs
N2 amplitudec Time x group 2.47 1, 108 0.022
Time x group x study 0.01 1, 108 < 0.001
P3a amplitude Time x group 1.14 1, 109 0.010
Time x group x study 4.76* 1, 109 0.042
P3b amplitude Time x group 0.36 1, 109 0.003
Time x group x study 1.95 1, 109 0.018
Physical fitness
PWC170d Time x group 1.52 1, 103 0.015
Time x group x study 0.02 1, 103 < 0.001
MABC-2e Time x group 0.99 1, 105 0.009
Time x group x study 0.18 1, 105 0.002 Notes: * = p < 0.05; a = corrected for age and body mass index; b = corrected for sex and pre- posttest changes in go reaction time; c = corrected for Intelligence and Developmental Scales – 2, value points derived from IQ screening items (naming categories and complete matrices); d = corrected for body mass index; e = corrected for Strengths and Difficulties sum score; ER = Error rate; ERPs = Event-related potentials; MABC-2 = Movement Assessment Battery for Children – 2nd edition; PWC170 = Relative physical working capacity at 170 bpm.
