Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2017 Oct;12(5):373-379.
doi: 10.1111/ijpo.12153. Epub 2016 Jun 2.

Cross-sectional and prospective impact of reallocating sedentary time to physical activity on children's body composition

Luís B Sardinha  1 , Adilson Marques  2 , Cláudia Minderico  1 , Ulf Ekelund  3   4
Affiliations
Randomized Controlled Trial

Cross-sectional and prospective impact of reallocating sedentary time to physical activity on children's body composition

Luís B Sardinha et al. Pediatr Obes. 2017 Oct.

Abstract

Background: The amount of time children spend in sedentary behaviours may have adverse health effects.

Objective: To examine the substitution effects of displacing a fixed duration of sedentary time with physical activity (PA) on children's body composition.

Methods: We included 386 children (197 boys). Outcomes were body mass index, waist circumference, total body fat mass and trunk fat mass assessed by dual-energy X-ray absorptiometry. Sedentary time and PA were measured with accelerometers. Data were analysed by isotemporal analyses estimating the effect of reallocating 15 and 30 min d-1 of sedentary time into light (light physical activity), and moderate-to-vigorous (MVPA) PA on body composition.

Results: Reallocating 15 and 30 min d-1 of sedentary time into MVPA was negatively associated with body fatness in cross-sectional analyses. Prospectively, reallocating 30 min of sedentary time into 30 min of MVPA was negatively associated with waist circumference (β = -1.11, p < 0.05), trunk fat mass (β = -0.21, p < 0.05), and total body fat mass (β = -0.48, p < 0.05) at follow-up (20 months). The magnitude of associations was half in magnitude and remained significant (p < 0.05) when reallocating 15 min of sedentary time into MVPA. Reallocating sedentary time into light physical activity was not related (p > 0.05) with body fatness outcomes.

Conclusions: Substituting sedentary time with MVPA using isotemporal analysis is associated with positive effects on body composition.

Keywords: Body composition; isotemporal; physical activity; sedentary time.

PubMed Disclaimer

Conflict of interest statement

Conflicts of interest statement

None to declare

References

    1. Marques A, Gaspar de Matos M. Adolescents' physical activity trends over the years: a three-cohort study based on the Health Behaviour in School-aged Children (HBSC) Portuguese survey. BMJ open. 2014;4:e006012. - PMC - PubMed
    1. Hallal PC, Andersen LB, Bull FC, Guthold R, Haskell W, Ekelund U. Global physical activity levels: surveillance progress, pitfalls, and prospects. Lancet. 2012;380:247–57. - PubMed
    1. Baptista F, Santos DA, Silva AM, et al. Prevalence of the Portuguese population attaining sufficient physical activity. Med Sci Sports Exerc. 2012;44:466–73. - PubMed
    1. Ekelund U, Luan J, Sherar LB, Esliger DW, Griew P, Cooper A. Moderate to vigorous physical activity and sedentary time and cardiometabolic risk factors in children and adolescents. JAMA. 2012;307:704–12. - PMC - PubMed
    1. Chinapaw MJ, Proper KI, Brug J, van Mechelen W, Singh AS. Relationship between young peoples' sedentary behaviour and biomedical health indicators: a systematic review of prospective studies. Obes Rev. 2011;12:e621–32. - PubMed

Publication types