This systematic review and meta-analysis examined the literature on early care and education center (ECEC)-based physical activity interventions to identify ecologic environmental factors that improve cardiovascular fitness (CVF) in preschool-aged children. Data sources included PubMed, Web of Science, Cochrane Library Trials, CINHAL, Science Direct, PsychINFO and SPORTDiscus. Peer-reviewed publications of studies that met the following criteria were eligible for inclusion: (1) mean age of participants between two and a half and five and a half years old enrolled in a pre-primary school; (2) randomized controlled trials or quasi-experimental interventions with a control group; (3) interventions occurring before, during, or immediately after school; (4) use of an objective measure or field-based estimate of CVF; (5) enrolled apparently healthy children. In June of 2018, titles (n = 1197) were reviewed for inclusion into the study and 74 abstracts/full texts were assessed for eligibility. Ten articles met all eligibility criteria and were included in the final review. A random effects meta-analysis suggested a moderate-to-large effect size for ECEC-based interventions to increase CVF (g = 0.75; 95%CI [0.40-1.11]). Interventions that included three or more ecologic environments (g = 0.79 [0.34-1.25]) were more effective than interventions occurring at the individual level (g = 0.67 [0.12-1.22]). Study quality was moderate, and (mean ± SD) 17.9 ± 4.3 (63.9%) of 28 checklist items were reported. Preliminary evidence suggests that ECEC-based interventions to increase CVF are highly effective at improving preschool children's exercise test scores. Although ECEC-based interventions show promise, the small number of studies included in this review limits confidence in these findings. Review registered at PROSPERO CRD42018099115.
Keywords: Cardiorespiratory fitness; Child; Physical activity; Preschool; Social ecology; Systematic review.