Table 4 Outcome variables, measuring instruments, covariates and intervention effects in reviewed studies sorted by age group

Ducheyne et al., 2014 [47]

Children

Cycling skills (objective: practical cycling test); AST: min of cycling to school (subjective: questionnaire); Psychosocial factors: attitudes towards cycling (subjective: questionnaire)

Baseline values of age, distance from home to school

Total basic cycling skills (adj.): group difference from pre to post, pre to follow-up and pre to post to follow-up with greater increase in IG(I/I + P) (p < 0.001, respectively), n.s. group difference from post to follow-up with greater increase in CG

Min of cycling to school last wk. (adj.): n.s. group difference from pre to post, pre to follow-up and pre to post to follow-up, group difference from post to follow-up with decrease in IG(I/I + P) and increase in CG (p < 0.05)

Parental attitudes towards cycling (adj.): n.s. group difference at any time point in importance/encouragement of cycling to school, importance of cycling skills/cycle training, encouragement of cycling skills improvement, impact of cycling training course on safer cycling behaviors in real traffic situations, and feeling of safety when cycling in traffic

Huang et al., 2018 [49]

Psychosocial factors: self-efficacy, outcome expectations (subjective: questionnaire)

Race/ethnicity, age, BMI z-score, bike score, sex/ gender, neighborhood disorder, distance from home to school

Child self-efficacy (adj.): group difference from pre to post (p < 0.05; β = 0.84 [CI95: 0.37, 1.31]) with increase in IG (β = 0.40 [CI95: 0.05, 0.75]) and decrease in CG (p < 0.05; β = − 0.43 [CI95: − 0.76, −0.11])

Parental self-efficacy (adj.): group difference from pre to post (p < 0.05; β = 0.46 [CI95: 0.05, 0.86]) with increase in IG (β = 0.21 [CI95: − 0.09, 0.51]) and decrease in CG (n.s.; β = − 0.25 [CI95: − 0.52, 0.03])

Parental outcome expectations (adj.): group difference from pre to post (p < 0.05; β = 0.47 [CI95: 0.17, 0.76]) with increase in IG (β = 0.14 [CI95: − 0.07, 0.36]) and decrease in CG (p < 0.05; β = − 0.32 [CI95: − 0.52, − 0.12])

Mendoza et al., 2017 [50]

AST: % of daily cycling trips to school (subjective: questionnaire); PA levels: MVPA (total, cycling, before/after school) in av. min/day (objective: accelerometer, GPS units)

Race/ethnicity, age, bike score, BMI z-score, sex/gender, neighborhood disorder, distance from home to school, accelerometer wear time

% of daily cycling trips to school (adj.): group difference from pre to post (p < 0.05; β = 44.9 [CI95: 26.8, 63.0]) with greater increase in IG (n.s.; β = 0.10 [CI95: − 0.02, 0.23])

Total MVPA in av. min/day (adj.): group difference from pre to post (p < 0.05; β = 21.6 [CI95: 8.7, 34.6]) with increase in IG and decrease in CG (n.s.; β = − 4.8 [CI95: − 13.6, 4.0])

Cycling MVPA in av. min/day (adj.): group difference from pre to post (p < 0.05; β = 23.0 [CI95: 10.7, 35.4]) with decrease in CG (n.s.; β = − 1.6 [CI95: − 10.0, 6.8])

Before/after school MVPA in av. min/day (adj.): group difference from pre to post (p < 0.05; β = 12.8 [CI95: 8.5, 17.2]) with decrease in CG (n.s.; β = − 0.9 [CI95: − 3.8, 2.1])

Østergaard et al., 2015 [45]

PA levels: LTPA beyond AST (subjective: questionnaire); AST: frequency of long/short-term school cycling (trips) (subjective: questionnaire); AT: frequency of cycling beyond school (subjective: questionnaire); Physical fitness (CRF): aerobic capacity (objective: Andersen test); Weight status: BMI (objective: digital scale, stadiometer)

Age, baseline BMI, baseline value, sex/ gender

LTPA beyond AST (adj.): n.s. group difference from pre to post with decrease in IG (β = − 0.09 [CI95: − 0.21, 0.03])

Frequency of long-term school cycling (adj.): n.s. group difference from pre to post with decrease in IG (β = − 0.02 [CI95: − 0.10, 0.05])

Frequency of short-term school cycling trips last wk. (adj.): n.s. group difference from pre to post with increase in IG (β = 0.15 [CI95: − 0.25, 0.54])

Frequency of cycling beyond school last wk. (adj.): n.s. group difference from pre to post with decrease in IG (β = − 0.04 [CI95: − 0.14, 0.05])

Aerobic capacity (adj.): group difference from pre to post with decrease in IG (p < 0.001; β = − 1.45 [CI95: − 1.92, − 1.00])

BMI (adj.): n.s. group difference from pre to post with increase in IG (β = 0.01 [CI95: − 0.13, 0.15])

Risk of developing overweight/obesity (adj.): n.s. group difference from pre to post with increase in IG (OR = 0.88 [CI95: 0.50, 1.57])

Dose response association between cycling to school and total intensity (adj.): n.s.

Villa-González et al., 2015 [51]

AST: mode/frequency of (active) trips to school (subjective: questionnaire)

Sex/gender, age, distance from home to school, pre/post AST variables, attendance

Mode of trips to school last wk. (adj.): n.s. group difference from pre to post in walking with greater increase in CG and biking with decrease in CG and no change in IG, group difference from post to follow-up in walking only with increase in IG and decrease in CG (p = 0.004)

Frequency of active trips to school last wk. (adj.): n.s. group difference from pre to post in walking and cycling with greater increase in CG, group difference from post to follow-up in walking and cycling with increase in IG and decrease in CG (p = 0.019)

Villa-González et al., 2017 [52]

AST: mode/frequency of (active) trips to school (subjective: questionnaire); Physical fitness: CRF (VO_2max, 20-m shuttle run test), muscular fitness (standing long jump, handgrip strength), speed agility (4 × 10 shuttle run test) (objective: ALPHA health-related fitness test battery)

Age, distance

Mode of trips to school last wk. (adj.): n.s. group difference from pre to post in walking, group difference from pre to post in cycling with increase in IG for male only and decrease in CG for male (p = 0.04)

Frequency of active trips to school last wk. (adj.): n.s. group difference from pre to post

CRF (adj.): group difference from pre to post in VO_2max with increase in CG for male only and decrease in IG for male and 20-m shuttle run test with increase in CG for male only and no change in IG for male (p < 0.05, respectively)

Muscular fitness (adj.): n.s. group difference from pre to post in standing long jump, group difference in handgrip strength with increase in CG in male only and decrease in IG for male (p < 0.05)

Speed agility (adj.): n.s. group difference from pre to post in 4 × 10 shuttle run test

Børrestad et al., 2012 [44]

Children/ Adolescents

Physical fitness (CRF): VO_2peak (objective: cycle ergometer), HR_peak (objective: heart rate monitor); Weight status: BMI, overweight (objective: beam scale, stationmeter); AST: start cycling (subjective: questionnaire)

Baseline level, sex/gender, age

VO_2peak (adj.): n.s. group difference from pre to post (d = − 0.13) with increase in IG [CI95: 47.5, 51.8] and CG [CI95: 48.5, 52.8]

HR_peak (adj.): n.s. group difference from pre to post (d = 0.03) with increase in IG [CI95: 189.4, 197.5] and decrease in CG [CI95: 189.2, 197.2]

BMI (adj.): n.s. group difference from pre to post (d = 0.01) with no change in IG [CI95: 18.5, 19.1] and increase in CG [CI95: 18.3, 13.9]

Overweight (adj.): n.s. group difference from pre to post with decrease in IG [CI95: 8.0, 33.7] and increase in CG [CI95: 7.7, 34.6]

Start cycling last 3 mos: n.s. group difference from pre to post with greater increase in IG [CI95: 50.1, 88.2] than CG [CI95: 20.9, 60.5]

Christiansen et al., 2014 [46]

AST: total no. of active trips to school (subjective: transport diary); Psychosocial factors: perceived route safety to school, encouragement of cycling to school, attitude towards cycling (subjective: questionnaire)

Age, baseline proportion of AST, distance to school, sex/ gender

Total no. of active trips to school for previous day over 5 days (adj.): n.s. group difference from pre to post with increase in IG and CG (OR = 1.27 [CI95: 0.81, 1.99]), n.s. gender effect with increase in male in IG and CG

Perceived route safety to school of student (adj.): n.s. group difference from pre to post with decrease in IG and increase in CG (OR = 0.87 [CI95: 0.50, 1.51])

Parental encouragement of cycling to school (adj.): n.s. group difference from pre to post with increase in IG and CG (OR = 1.26 [CI95: 0.92, 1.73])

Student attitude towards cycling (adj.): n.s. group difference from pre to post with decrease in IG and CG (OR = 1.50, [CI95: 0.90, 2.50])

Gutierrez et al., 2014 [48]

AST: counts of intersection crossings (objective: observation); Psychosocial factors: perception of safety, attitudes/beliefs towards AST (subjective: questionnaire)

NR

Counts of intersection crossings: n.s. group difference from pre to post in AST trends with increase in IG and CG, n.s. between-intersection effects from pre to post in no. of crossing guards (\( {\upeta}_{\mathrm{p}}^2 \) = 0.00), experimental intersections (\( {\upeta}_{\mathrm{p}}^2 \) = 0.00) or interaction of experimental and supervised intersections (\( {\upeta}_{\mathrm{p}}^2 \) = 0.01), increase in usage of supervised intersections in IG and CG (p = 0.041; \( {\upeta}_{\mathrm{p}}^2 \) = 0.08)

Parental perception of safety: no change (n.s.)

Parental attitudes/beliefs towards AST: no change (n.s.)