Accelerometer-derived physical activity levels of preschoolers: a meta-analysis

Area of Science:

• Pediatric physical activity research
• Exercise science
• Public health

Background:

• Accurate measurement of physical activity in preschoolers is crucial for developing effective health guidelines.
• Existing research on preschooler physical activity levels shows variability, necessitating a synthesized overview.
• Accelerometer-derived metrics are commonly used but require careful interpretation.

Purpose of the Study:

• To synthesize published estimates of daily moderate-to-vigorous physical activity (MVPA) in preschool-aged children (3-5 years).
• To provide a consolidated understanding of physical activity levels in this age group using accelerometer data.
• To highlight challenges in interpreting accelerometer-derived MVPA data.

Main Methods:

• A meta-analysis was conducted on previously published studies.
• A comprehensive literature search identified studies reporting accelerometer-derived MVPA in preschoolers up to March 2010.
• Random effects models were used to calculate point estimates and confidence intervals for MVPA in minutes and percentage of time, as well as accelerometer counts per minute (cpm).

Main Results:

• The meta-analysis included 29 articles representing 6309 preschoolers.
• Overall, preschoolers averaged 42.8 minutes of MVPA daily, with boys engaging in more activity than girls (54.4 min vs. 45.4 min).
• This equated to approximately 5.5% of daily time spent in MVPA, with boys at 7.1% and girls at 6.3%. Studies using ActiGraph accelerometers reported an average of 714 cpm.

Conclusions:

• Differences in accelerometer cut-point methodologies confound the interpretation of MVPA data in preschoolers.
• Caution is advised when using these activity levels to inform policy, including the development of physical activity guidelines.
• Standardization of accelerometer-derived MVPA measurement is needed for unbiased cross-study comparisons.