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Cited by 125Physical Activity and HealthObesity, Physical Activity, DietContext-Aware Activity Recognition Systems

Intraindividual Variation of Objectively Measured Physical Activity in Children

MATTOCKS, CALUM, LEARY, SAM, NESS, ANDY, DEERE, KEVIN, SAUNDERS, JOANNE, KIRKBY, JOANNE, BLAIR, STEVEN N., TILLING, KATE +1 more·2007·Medicine & Science in Sports & Exercise
DOI 10.1249/mss.0b013e318030631b
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Abstract

PURPOSE: This study examined the seasonal and intraindividual variation in objectively measured physical activity in 11- to 12-yr-olds. METHODS: Children were asked to wear a uniaxial accelerometer for 7 d four times throughout the course of about a year. A random-intercepts model was used to separate the inter- and intraindividual components of physical activity. Gender, age, body mass index (BMI), height, and month of measurement were fitted to the model as potential confounders. RESULTS: A total of 315 children had valid data for at least two measurement occasions, and 244 had data for all four measurement occasions. The unadjusted intraclass correlation coefficient (ICC) for total activity (counts per minute) was 0.54; 0.49 after adjusting for gender, age, and BMI; and 0.53 after adjusting for gender, age, BMI, and month. Further adjustment for pubertal status at baseline had no effect on the ICC. Restricting the analysis to only those with data for all four measurement occasions (N=244), or to measurements taken on school days only, had no effect on the ICC. The fully adjusted ICC was 0.51 for weekdays only and 0.39 for weekend days only. For minutes of moderate to vigorous physical activity, minutes of vigorous activity, minutes of sedentary behavior, and number of 30-min blocks of sedentary behavior, the fully adjusted ICC were 0.45, 0.37, 0.59, and 0.39, respectively. The analysis was repeated for boys and girls separately, but the differences in ICC were small. CONCLUSION: There was substantial intraindividual variation in the objectively measured physical activity of these children. Studies using single a measurement occasion where physical activity is the exposure should take this into account to adjust for regression dilution.

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  • Barriers to outdoor physical activity in one's yard or driveway, such as inclement weather or lack of outdoor space available at one's place of residence, may explain the pattern of displacement to home or garage.

    “Barriers to outdoor PA in one’s yard or driveway such as inclement weather [41, 42] (especially in the Northern states in late April) or lack of outdoor space available at one’s place of residence [43] may explain this pattern.”

    From Early effects of the COVID-19 pandemic on physical activity and sedentary behavior in children living in the U.S. (2020) · cites this paper as [42]

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Authors
MATTOCKS, C., LEARY, S., NESS, A., DEERE, K., SAUNDERS, J., KIRKBY, J., BLAIR, S. N., TILLING, K., & RIDDOCH, C.
Affiliations
  • University of Bristol (GB)
  • University of Glasgow (GB)
  • University of South Carolina (US)
  • University of Bath (GB)
ORCID
Venue
Medicine & Science in Sports & Exercise
Publisher
Ovid Technologies (Wolters Kluwer Health)
Published
2007-04
Volume
39
Issue
4
Pages
622-629
ISSN
0195-9131 (ISSN-L)
DOI
10.1249/mss.0b013e318030631b
OpenAlex
W2067717559
Cited by
125
References
27
Citations by year
2023: 1 · 2022: 7 · 2021: 3 · 2020: 4 · 2019: 5 · 2018: 7 · 2017: 8 · 2016: 6 · 2015: 5 · 2014: 8 · 2013: 13 · 2012: 11
FWCI
7.83
Type
journal article
Language
en
Open access
closed
Locations
  • Medicine & Science in Sports & Exercise (publishedVersion)
  • PubMed (publishedVersion)
  • Explore Bristol Research (publishedVersion)
  • Bristol Research (University of Bristol) (submittedVersion)
Funders
  • Wellcome Trust
  • National Heart, Lung, and Blood Institute (R01 HL071248-01A, R01HL071248)
Topics
  • Health Sciences › Medicine › Physiology › Physical Activity and Health
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Obesity, Physical Activity, Diet
  • Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Context-Aware Activity Recognition Systems
Keywords
within-person variability, physical activity, children, accelerometer-measured activity, intraclass correlation coefficient, seasonal variation, regression dilution, sedentary behavior, moderate-to-vigorous physical activity, measurement reliability, pubertal stage
MeSH terms
Child, Data Collection, Female, United Kingdom, Humans, Male, Seasons, Reproducibility of Results, Exercise, Monitoring, Ambulatory

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