Wearable Devices & the 24-hour Activity Cycle:
A Framework for Developing Daily Activity Recommendations

April 27-28th, 2016
Stanford University
MacKenzie Room, Huang Engineering Center

Workshop Organizing Committee:

William Haskell, PhD, Stanford Prevention Research Center, Stanford University
Richard Troiano, PhD, National Cancer Institute
Mary Rosenberger, PhD, Stanford Center on Longevity, Stanford University
Ken Smith, MS, Stanford Center on Longevity, Stanford University


Background The 2008 HHS Physical Activity Guidelines for Americans were developed primarily based on the association of self-reported physical activity data with health status. Related to the reliance on reported data, the focus of the Guidelines was limited to moderate and vigorous intensity physical activity (MVPA). Since 2008, there has been a rapid expansion in the use of accelerometer-based devices to obtain measures across the intensity spectrum (sleep, sedentary, light, moderate and vigorous intensity) during the entire day. These devices are currently available as both research and consumer products. The use of unobtrusive devices that provide information about the full spectrum of activity and inactivity provides an opportunity to consider a new paradigm to study physical activity and provide public health recommendations. The working hypothesis for this meeting is that health recommendations would be more effective if they could include all activity intensity-based domains rather than provide separate guidelines for different domains.
A framework for developing future guidelines encompassing each of the activity-intensity domains will include the 24-hour activity cycle (24-HAC). Using the 24-HAC could be a major advance to provide guidance to health professionals and the public on how individuals should spend their day for optimal health. For this workshop, the 24-HAC domains to be included in the discussion are sleep, sedentary behavior (sitting and reclining while awake), light-intensity activity (including standing), moderate-intensity and vigorous-intensity physical activity.

Workshop Goals

1. Summarize the state of the science regarding the health effects of physical activity and sedentary behavior as established by (a) self-report and (b) device measurements for     each of the 24-HAC domains.
2. Discuss innovation and issues regarding the accurate and reliable measurement of the 24-HAC domains using wearable devices.
3. Review the status of the collection, storage, management and analysis of data in each 24-HAC domain
4. Consider alternatives to the 24-HAC for analyzing and presenting comprehensive physical activity recommendations
5. Review analytical approaches to determine the health consequences of exchanging time in one 24-HAC domain for time in another domain
6. Identify current large databases containing data for the entire 24-HAC
7. Develop research priorities to advance objective assessment in each of the 24-HAC domains.
** Workshop goals include the preparation of a report or white paper on use of objective and self-report measures of PA in constructing PA guidelines.