Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Apr 13;10(4):e0121238.
doi: 10.1371/journal.pone.0121238. eCollection 2015.

Physical education: the effect of epoch lengths on children's physical activity in a structured context

Alberto Aibar  1 , Julien Chanal  2
Affiliations

Physical education: the effect of epoch lengths on children's physical activity in a structured context

Alberto Aibar et al. PLoS One. .

Abstract

Background: Despite a consensus emerging that affirms that shorter epochs should be used in youth to correctly register physical activity levels in free-living conditions, little is known about its effect on children's physical activity conducted in structured periods of time. This study analyzed the effect that epoch length (1, 2, 3, 5, 10, 15, 30 and 60s) may have on different physical activity intensities in physical education lessons.

Methods: A sample of 1912 individual measures of physical education lessons were measured with a GT3X accelerometer. Data were collected from 1227 Swiss Elementary school students recruited in 17 elementary schools. PE lessons lasted from 45 minutes to one and a half hours. Data, originally collected in 1-s epoch, were then reintegrated into 2s, - 3s - 5s - 10s - 15s - 30s -60s epochs.

Results: Longer epochs were associated with higher levels of light (F = 8197.6, p < .001), moderate (F = 2708.17, p < .001), and moderate-to-vigorous physical activity (F = 888.08, p < .001). However, longer epochs showed lower levels of sedentary activity (F = 31714.33, p < .001) and vigorous physical activity (F = 1910.97, p < .001). Bias increased in all PA intensities when shorter epochs were compared with longer epochs. There were statistically significant differences in compliance with physical education guidelines (χ(2) = 989.27, p<.001), showing higher levels with longer epochs.

Conclusion: PA context may have some influence on the effects that epoch length have on PA estimates, more specifically on MVPA. Nevertheless, the use of a high-frequency sampling interval should be used to more accurately assess children's PA.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Percentages of sedentary, light, moderate and vigorous physical activity by epoch length for all PE lessons.
Fig 2
Fig 2. Bias and 95% confidence intervals for each epoch for Sedentary, Light, Moderate and Vigorous Activity.
Fig 3
Fig 3. Differences between short and long PE lessons by epoch for each PA intensity.
Note: Values are expressed in minutes. Values of long lessons have been subtracted from short lessons.
See this image and copyright information in PMC

References

    1. Plasqui G, Bonomi AG, Westerterp KR. Daily physical activity assessment with accelerometers: new insights and validation studies. Obes rev. 2013; 14: 451–462. 10.1111/obr.12021 - DOI - PubMed
    1. Reilly JJ, Penpraze V, Hislop J, Davies G, Grant S, Paton JY. Objective measurement of physical activity and sedentary behaviour: Review with new data. Arch Dis Child. 2008; 93: 614–619. 10.1136/adc.2007.133272 - DOI - PubMed
    1. Bailey RC, Olson J, Pepper SL, Porszasz J, Barstow TJ, Cooper DM. The level and tempo of children's physical activities: An observational study. Med Sci Sports Exerc. 1995; 27: 1033–1041. - PubMed
    1. Baquet G, Stratton G, Van Praagh E, Berthoin S. Improving physical activity assessment in prepubertal children with high-frequency accelerometry monitoring: A methodological issue. Prev Med. 2007; 44: 143–147. - PubMed
    1. Berman N, Bailey R, Barstow TJ, Cooper DM. Spectral and bout detection analysis of physical activity patterns in healthy, prepubertal boys and girls. Am J Hum Biol. 1998; 10: 289–97. - PubMed

Publication types

LinkOut - more resources