Physical activity intensity, bout-duration, and cardiometabolic risk markers in children and adolescents.
Int J Obes (Lond)
; 42(9): 1639-1650, 2018 09.
Article
in En
| MEDLINE
| ID: mdl-30006582
ABSTRACT
OBJECTIVES:
To determine the role of physical activity intensity and bout-duration in modulating associations between physical activity and cardiometabolic risk markers.METHODS:
A cross-sectional study using the International Children's Accelerometry Database (ICAD) including 38,306 observations (in 29,734 individuals aged 4-18 years). Accelerometry data was summarized as time accumulated in 16 combinations of intensity thresholds (≥500 to ≥3000 counts/min) and bout-durations (≥1 to ≥10 min). Outcomes were body mass index (BMI, kg/m2), waist circumference, biochemical markers, blood pressure, and a composite score of these metabolic markers. A second composite score excluded the adiposity component. Linear mixed models were applied to elucidate the associations and expressed per 10 min difference in daily activity above the intensity/bout-duration combination. Estimates (and variance) from each of the 16 combinations of intensity and bout-duration examined in the linear mixed models were analyzed in meta-regression to investigate trends in the association.RESULTS:
Each 10 min positive difference in physical activity was significantly and inversely associated with the risk factors irrespective of the combination of intensity and bout-duration. In meta-regression, each 1000 counts/min increase in intensity threshold was associated with a -0.027 (95% CI -0.039 to -0.014) standard deviations lower composite risk score, and a -0.064 (95% CI -0.09 to -0.038) kg/m2 lower BMI. Conversely, meta-regression suggested bout-duration was not significantly associated with effect-sizes (per 1 min increase in bout-duration -0.002 (95% CI -0.005 to 0.0005) standard deviations for the composite risk score, and -0.005 (95% CI -0.012 to 0.002) kg/m2 for BMI).CONCLUSIONS:
Time spent at higher intensity physical activity was the main determinant of variation in cardiometabolic risk factors, not bout-duration. Greater magnitude of associations was consistently observed with higher intensities. These results suggest that, in children and adolescents, physical activity, preferably at higher intensities, of any bout-duration should be promoted.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Exercise
/
Physical Conditioning, Human
Type of study:
Etiology_studies
/
Observational_studies
/
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adolescent
/
Child
/
Child, preschool
/
Humans
Language:
En
Journal:
Int J Obes (Lond)
Journal subject:
METABOLISMO
Year:
2018
Type:
Article
Affiliation country:
Denmark