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Combining accelerometry and HR for assessing preschoolers' physical activity
Freia De Bock1, Jochen Menze, Simone Becker
1Mannheim Institute of Public Health, Social and Preventive Medicine, University Medicine Mannheim, Heidelberg University, Mannheim, Germany. freia.debock@medma.uni-heidelberg.de
Insights
Accurate physical activity (PA) measurement in preschoolers is crucial. Combined heart rate (HR) and accelerometry (ACC) effectively classify moderate-to-vigorous PA but are less accurate for sedentary behavior.
Area of Science:
- Pediatric physical activity assessment
- Biometric monitoring in children
- Childhood obesity research
Background:
- Rising childhood obesity necessitates accurate physical activity (PA) measurement for early intervention.
- Existing PA measurement methods using accelerometry (ACC) and heart rate (HR) are validated in older children but not preschoolers.
- Preschooler PA classification accuracy using combined ACC and HR is currently unknown.
Purpose of the Study:
- To evaluate the utility of combined accelerometry (ACC) and heart rate (HR) monitoring for accurately classifying physical activity (PA) intensity in preschoolers.
- To determine gender-specific cutoffs for ACC and HR to classify moderate-to-vigorous PA (MVPA) and sedentary behavior (SB) in young children.
- To compare the classification accuracy of combined ACC/HR data versus ACC alone for different PA intensities.
Main Methods:
- Thirty-three preschoolers underwent direct observation using the Children's Activity Rating Scale (CARS) and simultaneous Actiheart monitoring (ACC and HR).
- Data were divided into derivation and validation sets to establish and test gender-specific ACC and HR cutoffs for classifying MVPA (CARS 4-5) and SB (CARS 1-2).
- Receiver operating characteristic (ROC) analysis was employed to determine optimal cutoffs and assess classification accuracy.
Main Results:
- Combined HR and ACC cutoffs achieved high accuracy in classifying moderate-to-vigorous PA (MVPA): 91% for girls and 87% for boys.
- Classification accuracy for sedentary behavior (SB) was lower when using combined HR and ACC cutoffs.
- ACC cutoffs alone yielded higher classification rates for SB (69% girls, 67% boys) compared to combined cutoffs.
Conclusions:
- Devices combining heart rate (HR) and accelerometry (ACC) accurately classify moderate-to-vigorous physical activity (MVPA) in preschoolers.
- The accuracy of combined HR and ACC for classifying sedentary behavior (SB) in this age group is limited.
- Matching PA evaluation methods to intervention objectives is essential for effective childhood obesity prevention and management strategies.
Purpose:
With rising obesity and rapidly decreasing levels of physical activity (PA) in young children, accurate PA measurement is needed for early screening and intervention evaluation. Although the combination of accelerometry (ACC) with HR recordings is accurate in assessing PA intensity in older children, its utility in correctly classifying PA in preschoolers is unknown.
Methods:
Thirty-three children (64% were boys) were recruited from four German preschools. Data included direct observation and Actiheart (CamNtech, Cambridge, UK) monitoring during 2.5 T 0.7 h (derivation data) and 1.5 T 0.3 h (validation data). Observers assessed PA using the Children's Activity Rating Scale (CARS). Moderate-to-vigorous PA (MVPA) was defined by a CARS score of 4 or 5, and sedentary behavior (SB) was defined by a CARS score of 1 or 2. Actiheart recordings were linked to CARS level, with means and 95% confidence intervals calculated for ACC and HR at each observed CARS level and for MVPA/SB. Using receiver operating characteristic analysis, gender-specific ACC and HR cutoffs for correctly classifying MVPA and SB were first determined in a derivation data set and then tested in a separate validation data set of observations.
Results:
By combining HR and ACC cutoffs, 91% and 87% of the 15-s intervals observed as MVPA were correctly classified in girls and boys, respectively. Although generally lower, correct classification rates for SB were highest when only ACC cutoffs were applied (69% for girls and 67% for boys) rather than when combined cutoffs were used.
Conclusions:
Devices that combine HR and ACC data yield an accurate classification of MVPA in preschoolers but perform less well for classifying SB. These differences underscore the need to match evaluation methods with the objectives of future PA interventions.
