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Published on: March 7, 2019
Habitual physical activity and physical activity intensity: their relation to body composition in 5.0-10.5-y-old
1School of Human Movement Studies, University of Queensland, St Lucia, Australia. rebecca@hms.uq.edu.au
Insights
Higher intensity physical activity in children is linked to lower body fat. This study suggests a threshold of activity intensity may be crucial for managing childhood obesity.
Area of Science:
- Pediatric Endocrinology
- Exercise Physiology
- Childhood Obesity Research
Background:
- Global concerns exist regarding declining physical activity levels (PALs) in children and rising childhood obesity rates.
- The precise relationship between physical activity and body composition in children requires further elucidation.
Purpose of the Study:
- To investigate the association between habitual physical activity, intensity of activity, and body composition in children aged 5-10.5 years.
- To determine if specific activity intensities correlate with body fatness and Body Mass Index (BMI).
Main Methods:
- Total Energy Expenditure (TEE) measured via doubly labeled water technique.
- Physical Activity Level (PAL) calculated as TEE/Basal Metabolic Rate (BMR).
- Activity intensity and duration assessed using accelerometry (Tritrac-R3D); body composition evaluated by body fat percentage and BMI.
Main Results:
- Significant inverse correlations were found between PAL and both body fat percentage (r=-0.43) and BMI (r=-0.45).
- Vigorous and hard intensity activities showed significant inverse correlations with body fat percentage (r=-0.44 and r=-0.39, respectively), but not BMI.
- Children engaging in higher levels of vigorous and hard activity exhibited significantly lower body fat percentages.
Conclusions:
- A significant relationship exists between PAL and body composition in children.
- Evidence suggests a potential threshold of physical activity intensity that influences body fatness.
- Findings underscore the importance of physical activity intensity for children's body composition and warrant further investigation amidst rising childhood obesity trends.
Background:
Concerns of a decrease in physical activity levels (PALs) of children and a concurrent increase in childhood obesity exist worldwide. The exact relation between these two parameters however has as yet to be fully defined in children.
Objective:
This study examined the relation in 47 children, aged 5-10.5 y (mean age 8.4+/-0.9 y) between habitual physical activity, minutes spent in moderate, vigorous and hard intensity activity and body composition parameters.
Design:
Total energy expenditure (TEE) was calculated using the doubly labelled water technique and basal metabolic rate (BMR) was predicted from Schofield's equations. PAL was determined by PAL=TEE/BMR. Time spent in moderate, vigorous and hard intensity activity was determined by accelerometry, using the Tritrac-R3D. Body fatness and body mass index (BMI) were used as the two measures of body composition.
Results:
Body fat and BMI were significantly inversely correlated with PAL (r=-0.43, P=0.002 and r=-0.45, P=0.001). Times spent in vigorous activity and hard activity were significantly correlated to percentage body fat (r=-0.44, P=0.004 and r=-0.39, P=0.014), but not BMI. Children who were in the top tertiles for both vigorous activity and hard activity had significantly lower body fat percentages than those in the middle and lowest tertiles. Moderate intensity activity was not correlated with measures of body composition.
Conclusions:
As well as showing a significant relation between PAL and body composition, these data intimate that there may be a threshold of intensity of physical activity that is influential on body fatness. In light of world trends showing increasing childhood obesity, this study supports the need to further investigate the importance of physical activity for children.
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