Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article


Doctor of Philosophy


Health and Rehabilitation Sciences


Irwin, Jennifer. D.


Undergraduate students (UGS) are highly sedentary, which may elevate their health risks. However, before the effectiveness of an undergraduate sedentary time (ST) intervention can be assessed, accurate and applicable measurement tools need to be identified. The overall purposes of this research program were to first, evaluate the validity of two weekly ST questionnaires compared with criterion data in homogenous samples of UGS (Studies 1 and 2); and second, to measure the effect of providing UGS with mobile standing desks for one-week (Study 3) and one-month (Study 4), while also exploring students’ perceptions about using the desks. Each study built on the findings of the study that came before it, with Studies 1 and 2, and Studies 3 and 4 presented together.

In Study 1, UGS wore the activPAL4TM for one week and then completed the PAST-WEEK-U (PWU). In Study 2, UGS wore the activPAL4TM for one week and simultaneously completed the NIGHTLY-WEEK-U (NWU). The agreement between the self-report and criterion measures were assessed via Bland-Altman plots. In Study 3, UGS were provided with a mobile standing desk for one week and their ST was measured using the activPAL4TM and NWU. In Study 4, UGS were provided with a mobile standing desk for one month and their ST was measured with an online version of the NWU. Semi-structured interviews (Study 3) and online opened-ended questions (Study 4) explored participants’ experiences with the desks.

The results of Studies 1 and 2 revealed that the NWU outperformed the PWU with much tighter limits of agreement (-1.75 to 2.17 vs. -5.38 to 5.55 hours), making it better suited for use in future intervention studies. In Studies 3 and 4, mobile standing desks were associated with a significant reduction in one-week (objective: p= 0.0045; self-report: p= 0.0005) and one-month (self-report: p=

This dissertation’s studies are valuable for future intervention research aimed at UGS ST, and may contribute to future health gains for an expanding and important population.

Summary for Lay Audience

The daily sedentary time (ST) of undergraduate students (UGS) is too high and could negatively affect their health. This research program had two main objectives: (1) to establish a questionnaire that could accurately estimate the daily ST of UGS; and (2) determine the impact of mobile standing desks on the daily ST of UGS, while also understanding their experiences with the desks. These two objectives were divided into four research studies.

Study 1 compared the accuracy of a past-week ST questionnaire, the PAST-WEEK-U (PWU), to a device capable of near perfect ST measurement, the activPAL4TM. The daily ST measured by the PWU was compared to the daily ST measured by the activPAL4TM. The comparison was not favorable as many participants under- and over-estimated their ST by large amounts.

Study 2 compared the accuracy of a week-long ST questionnaire, the NIGHTLY-WEEK-U (NWU), with the activPAL4TM. Participants completed the NWU on each day of the week, instead of at the end. Daily ST was compared between the NWU and the activPAL4TM. The NWU was much more accurate than the PWU from Study 1 and was deemed acceptable for use in future studies.

In Study 3, UGS were provided with mobile standing desks for one week to test the usefulness of the desks and asked questions about their experience immediately afterwards. Daily ST from one week without the desk (baseline) was compared to daily ST of a week with the desk (intervention), measured using the activPAL4TM and the NWU. Students mostly enjoyed the desks and reduced their ST significantly.

Study 4 involved providing UGS with the mobile standing desks for one month to test the long-term suitability of the desks and asking them questions online following the intervention. Daily ST from a baseline week was compared to that of an intervention week, which occurred one month after students received their desk. Students mostly enjoyed using the desks and reduced their ST significantly, but some became bored with the desks.

This research program could help future researchers measure and intervene with the ST of UGS, ultimately improving student health.