Functional endurance capacity is associated with multiple other physical fitness components in 7–14-year-olds: a cross-sectional study

BACKGROUND: Although evidence suggests that functional endurance capacity is the most important component associated with future health, little is known of how it is associated with multiple other physical fitness components. Since various physical fitness aspects do not change the same as functional endurance capacity during childhood, it is necessary to establish possible associations between functional endurance capacity and other physical fitness components in children. Therefore, the main purpose of the study was to test the associations between functional endurance capacity with other physical fitness components in 7–14-year-old children, stratified by gender. METHODS: In this cross-sectional study, we recruited 1612 children [mean age ± standard deviation (SD) = 9.72 ± 2.37 years; 52.5% girls). Health-related physical fitness components included: 1) body-mass index (kg/m(2)) calculated from height and weight (measure of body size), 2) sit-and-reach test (measure of flexibility), 3) standing broad jump (measure of explosive strength of lower extremities), 4) sit-ups in 30 s (measure of repetitive strength of the trunk), 5) 10 × 5 shuttle run test (measure of agility) and 6) 20-m shuttle run test (measure of functional endurance capacity). The associations were performed using generalized estimating equations with beta (β) coefficients. RESULTS: After adjusting for age, functional endurance capacity was associated with sit-and-reach test (β = 0.13, p < 0.001), standing broad jump (β = 0.59, p < 0.001), sit-ups in 30 s (β = 0.53, p < 0.001) and 10 × 5 shuttle run test (β = − 0.56, p < 0.001) in boys. In girls, functional endurance capacity was associated with body-mass index (β = − 0.12, p < 0.001), sit-and-reach test (β = 0.21, p < 0.001), standing broad jump (β = 0.25, p < 0.001), sit-ups in 30 s (β = 0.36, p < 0.001) and 10 × 5 shuttle run test (β = − 0.40, p < 0.001). No significant associations between functional endurance capacity and body-mass index in boys were observed. CONCLUSIONS: Although significant, functional endurance capacity is weakly to moderately associated with other physical fitness components, pointing out that such measure should be tested separately from other aspects of physical fitness in school-aged children.