Length of moderate-to-vigorous physical activity bouts and cardio-metabolic risk factors in elementary school children

Accumulating moderate-to-vigorous physical activity (MVPA) in bouts of 10 min is associated with improved cardio-metabolic risk factors (CMRF) in adults.To assess the association between the lengths of MVPA bouts and CMRF in elementary school age children.The sample included 396, 2nd and 3rd grade students from eastern Kansas (182 boys, 214 girls; age 7.6 ± 0.6 years; Body Mass Index Percentile [BMI%ile]: 61.6 ± 9.3) in the fall of 2011. Analyses were conducted in 2014. MVPA bouts were defined as sporadic (<5 min), short (5-<10 min) or medium-to-long (≥10 min). Latent profile analysis was used to identify distinct subgroups (classes) based on the composition of MVPA bouts. Bayesian probability-based Wald chi-square test was used to compare CMRF between classes controlling for age, sex, BMI%ile, and total moderate and total vigorous PA.Three classes of accumulated physical activity were identified: A (n=78); 97% sporadic 2%, short, 1% medium-to-long bouts; B (n=174); 93% sporadic, 5%