How should we choose the most appropriate Epoch-Length for Children’s Physical Activity?

Oral Presentation B4.5


  • Claudio R. Nigg University of Bern
  • Carina Nigg University of Bern; Karlsruhe Institute of Technology
  • Mihyun Kim Colorado State University
  • Julia Sharp Colorado State University
  • Xanna Burg Montana Budget and Policy Center
  • Leslie Cunningham-Sabo Colorado State University



Children, Physical Activity, Measurement, Epochs, Bouts


Background: It is unclear how epoch length (EL) influences children’s physical activity prevalence and relationships with health outcomes. Purpose: To investigate the impact of different ELs (1-15, 30, and 60 seconds, 2, 5, 10, 30, and 60 minutes) for children on: a) meeting World Health Organization physical activity guidelines; and b) physical activity and BMI relationship. Methods: Children (n=460, age=9.14 (SD=0.35) years, 50.7% female, 73.0% white, and 26.1% overweight/obese) wore a wrist-mounted GENEactiv accelerometer for one week. Results: For 1-, 15-s, and 10-min EL, children accumulated 116.29 (SD=30.56), 21.59 (SD=12.29), and 0.04 (SD=0.56), moderate-to-vigorous physical activity minutes/day, respectively, with no MVPA for 30 and 60 minutes. The shorter the EL, the more children met physical activity guidelines; 85.7%, 32.9%, and 0.4% of children met physical activity guidelines at 1-, 5-, and at 15-s ELs, respectively. For the two shortest ELs, there were no sex differences, whereas from 3- to 13-s EL, boys had higher prevalence than girls. The strongest correlation between moderate-to-vigorous physical activity and BMI z-score was around 6-s EL (for boys between 8-10-s ELs (r=-0.070 to r=-0.072), for girls between 3-6-s EL (r=-0.034 to r=-0.037)). Conclusions: For this sample, around 5+/-1-s seems the most appropriate EL for physical activity in children. For generalizibility, replication with other samples is needed. The very short EL’s and the sex difference’s impact on morbidity and mortality should be further investigated. Funding: National Institute of Food and Agriculture, U.S. Department of Agriculture, award number 2012-68001-19603.



How to Cite

Nigg, C., Nigg, C., Kim, M., Sharp, J., Burg, X., & Cunningham-Sabo, L. (2021). How should we choose the most appropriate Epoch-Length for Children’s Physical Activity? Oral Presentation B4.5. The Health & Fitness Journal of Canada, 14(3).

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