Cardiovascular adaptations after 10 months of intense school‐based physical training for 8‐ to 10‐year‐old children

This study examined cardiovascular adaptations in 8‐ to 10‐year‐old schoolchildren after 10 months (a full school year) of 3 × 40 minute per week of small‐sided ball games ( SSG , including football, basketball, and/or floorball) or circuit strength training ( CST ). The study involved 291 Danish schoolchildren, 8‐10 years old, cluster‐randomized to SSG (n = 93, 4 schools, 5 classes), CST (n = 83, 4 schools, 4 classes), or a control group ( CON , n = 115, 2 schools, 5 classes). Before and after the 10‐month intervention, resting heart rate and blood pressure measurements were performed as well as comprehensive transthoracic echocardiography and peripheral arterial tonometry ( PAT ). Analysis of baseline‐to‐10‐months changes showed between‐group differences ( P < 0.05) after both training interventions in diastolic blood pressure (delta scores: SSG −2.1 ± 6.0 mm Hg; CST −3.0 ± 7.1 mm Hg; CON 0.2 ± 5.3 mm Hg). Moreover, there were between‐group differences in delta scores ( P < 0.05) in interventricular septum thickness ( SSG 0.17 ± 0.87 mm; CST 0.30 ± 0.94 mm; CON −0.15 ± 0.68 mm), left‐atrial volume index ( SSG 0.32 ± 5.13 mL/m 2 ; CON 2.60 ± 5.94 mL/m 2 ), and tricuspid annular plane systolic excursion ( SSG −0.4 ± 3.3 mm; CON : 0.1 ± 3.6 mm). No significant between‐group differences were observed for the PAT ‐derived reactive hyperemia index. In conclusion, 10 months of 3 × 40 minutes per week of SSG and CST in 8‐ to 10‐year‐old children decreased diastolic blood pressure and elicited discrete cardiac adaptations, suggesting that intense physical exercise in school classes can have effects on cardiovascular health in children.