Angelo N. Belcastro

Purpose : Children’s poor levels of physical activity (PA) participation and early-onset vascular aging are identified as global health challenges. Children’s guided activity play (GAP)-based PA programs have emerged as effective strategies to improve cardiovascular risk factors and health-related fitness. This study proposes to investigate whether GAP improves children’s cutaneous microvascular reactivity and health-related fitness. Methods : Children’s (n = 18; 9.8 [1.5] y) PA during a 5-week (4 d/wk; 1 h/d) GAP program was assessed (accelerometry) with preassessments and postassessments for anthropometric, musculoskeletal fitness, blood pressure, estimated aerobic power, and cutaneous microvascular reactivity. Results : PA averaged 556 (132) kcal·week −1 at 34.7% (7.5%) time at moderate to vigorous intensity. Resting heart rate (−9.5%) and diastolic blood pressure (−7.8%) were reduced without changes in health-related fitness indices. Cutaneous microvascular reactivity to sodium nitroprusside iontophoresis increased the average perfusion (+36.8%), average cutaneous vascular conductance (+30%), the area under the curve (+28.8%), and a faster rise phase (+40%) of perfusion (quadratic modeling; P ≤ .05). Chi-square and crosstabulation analysis revealed significant association between children’s PA levels and sodium nitroprusside average perfusion levels, where children with PA levels ≥205.1 kcal . 55 minute −1 were overrepresented in the medium/high levels of sodium nitroprusside perfusion. Conclusion : A 5-week GAP modified the microvascular reactivity in children without changes in body mass, musculoskeletal fitness, or estimated aerobic power.