Effects of a cluster-randomized exercise intervention on cardiovascular health in preschoolers.

Primary health prevention in at-risk children is receiving increased attention while less information is available on cardiovascular profile and response to exercise in healthy children. Our study examined the effects of a gross motor skill-based exercise intervention on micro- and macro-vascular health in preschoolers. This is a sub-study of a five-armed clinical trial with six kindergartens and 68 children. Four kindergartens were assigned to the intervention group (INT) and two to control groups (CON). We performed gross motor skill assessment (TGMD-2), static retinal vessel analysis, and measurements of central hemodynamics before and after the intervention. INT received one weekly exercise session for 25 weeks, while CON received no intervention. We calculated linear regressions correcting for age, sex, BMI-percentile, and baseline. We observed favorable effects in TGMD-2 for INT over CON (Cohen's d = 0.52 95% CI [0.15; 0.90]). Trivial between-group differences were observed in retinal vessel diameters (0.08 < d ≤ 0.29) and trivial to moderate differences in all other arterial stiffness parameters (-0.55 < d ≤ 0.31). Motor-skill based interventions are sensible measures to incorporate physical activity in pre-schools and improve gross motor proficiency at a very young age. The potential of motor skill-based interventions as primordial prevention strategy in healthy preschoolers needs to be further investigated.