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Foundational Research

Research on the YAP
The Physical Self-Perception Profile was developed by.....


​Youth Activity Profile (YAP) is a self-report instrument designed to facilitate the collection of physical activity in schools (for both assessment and education purposes). The instrument was developed by our team and calibrated through a series of studies led by a former Ph.D. student (Dr. Pedro Saint-Maurice) as part of his dissertation research. The innovative aspect of the Youth Activity Profile is that the items are calibrated to provide accurate estimates of physical activity (PA) and sedentary behavior. The figure below shows the concept of calibration and the overall level of agreement for assessing PA in different segments of the day. 

Extensions and Applications 

The PSPP has been used.... 

online version of the YAP was developed to facilitate use by schools and an NIH funded study by the lab replicated the calibration process with the online tool. The new online version provides updated calibration equations using a larger and more diverse sample and more robust prediction models. The focus of the research was on evaluating the utility for school-based applications. Observed errors for estimating time spent in physical activity and sedentary behavior were 15-25% for the different school based settings with good consistency across schools. Results for the different segments are in the figures below.
  1. Frömel, K., Welk, G., Groffik, D., Jakubec, L., Dygrýn, J., & Mitáš, J. (2025). Adolescent physical activity during school days: a comparative study before and after COVID-19 pandemic restrictions. Frontiers in Public Health, 13, 1488153.
  2. Von Seggern, M. J., Rogers, A. E., Schenkelberg, M. A., Kellstedt, D. K., Welk, G. J., High, R., & Dzewaltowski, D. A. (2024). Sociodemographic influences on youth sport participation and physical activity among children living within concentrated Hispanic/Latino rural communities. Frontiers in Public Health, 12, 1345635.
  3. Kellstedt DK, Essay AM, Schenkelberg MA, Rosen MS, Von Seggern MJ, Idoate R, Welk GJ, Rosenkranz RR, Dzewaltowski DA. (2022). COVID-19 pandemic and changes in children’s physical activity in a rural US community: a mixed methods study. BMJ open, 12(10), e062987.
  4. Schenkelberg, M. A., Essay, A. M., Rosen, M. S., Bavari, A. E., Norgelas, S. J., Rosenkranz, R. R., Welk, G. J, Dzewaltowski, D. A. A protocol for coordinating rural community stakeholders to implement whole-of-community youth physical activity surveillance through school systems. Preventive Medicine Reports (2021). doi:10.1016/j.pmedr.2021.101536
  5. Welk, G.J., Saint-Maurice, P.F., Dixon, P.M., Hibbing, P.R., Bai, Y., McLoughlin, G.M., Pereira da Silva, M. (2021). Calibration of the Online Youth Activity Profile Assessment for School-Based Applications. Journal for the Measurement of Physical Behavior.
  6. Kellstedt D, Schenkelberg MA, Essay AM, Von Seggern M., Rosenkranz RR, Welk GJ, High R, and Dzewaltowski DA. Youth sport participation and physical activity in rural communities. Archives of Public Health. 2021. doi.org/10.1186/s13690-021-00570-y
  7. Welk, G. J., Saint-Maurice, P. F., Kim, Y., Ellingson, L. D., Hibbing, P., Wolff-Hughes, D. L., & Perna, F. M. (2017). Understanding and interpreting error in physical activity data: insights from the FLASHE study. American journal of preventive medicine, 52(6), 836-838.
  8. Saint-Maurice, P. F., Kim, Y., Hibbing, P., Oh, A. Y., Perna, F. M., & Welk, G. J. (2017). Calibration and validation of the Youth Activity Profile: the FLASHE study. American Journal of Preventive Medicine, 52(6), 880-887.
  9. Saint-Maurice, P. F., Welk, G. J., Bartee, R. T., & Heelan, K. (2016). Calibration of context-specific survey items to assess youth physical activity behaviour. Journal of Sports Sciences, June 1-7.
  10. Saint-Maurice, P. F., Kim, Y., & Welk, G. J. (2016). Evidence for data missing at random in youth physical activity monitoring research. Journal of Sports Sciences, April: 1-7.
  11. Saint-Maurice, P. F., Kim, Y., Welk, G. J., & Gaesser, G. A. (2016). Kids are not little adults: what MET threshold captures sedentary behavior in children? European Journal of Applied Physiology, 116(1), 29-38.
  12. Saint-Maurice, P. F., & Welk, G. J. (2015). Validity and Calibration of the Youth Activity Profile. PloS one, 10(12).
  13. Saint-Maurice, P. F., Welk, G. J., Beyler, N. K., Bartee, R. T., & Heelan, K. A. (2014). Calibration of self-report tools for physical activity research: the Physical Activity Questionnaire (PAQ). BMC Public Health, 14(1), 461. PMID: 24886625

Requesting Access to the OnLine Version of the YAP

An online version of the YAP is available for use by schools / districts through the Active Schools initiative. ​A separate version is also available for customization and use by researchers. Visit the online tool at www.youthactivityprofile.org to learn more. Additional information is also available from Dr. Greg Welk ([email protected].