Studying Contextual and Psychological Predictors of Physical Activity Among Emerging Adults: Protocol for an...

Many adults are insufficiently active, posing a threat to public health. Research shows steep declines in physical activity during the emerging adulthood period. Psychological and socioenvironmental factors have been shown to be independently associated with engaging in physical activity. However, few studies have examined the cross-domain interactions between psychological and socioenvironmental factors on physical activity in real time. Real-time data collection methods can be leveraged alongside traditional nomothetic methods to gain a more comprehensive understanding of how physical activity is affected by dynamic changes to one's unique psychological and contextual state within a day.

This paper describes the protocol for a study aiming to examine independent and interactive associations between psychological and contextual factors and real-time physical activity in emerging adults. Ecological momentary assessment (EMA) and device-based monitoring of physical activity will be used.

The SCOPE (Studying COntextual and Psychological predictors of physical activity among Emerging adults) study will use an intensive longitudinal study design. A total of 124 emerging adults will be recruited, completing 2 waves of data collection consisting of an online survey followed by 7 days of EMAs 6 months apart. EMA surveys will be administered using the Pathverse smartphone app, and physical activity will be assessed using a Fitbit Versa 4 activity monitor.

The study was approved by the research ethics board at the University of Waterloo in November 2025. Recruitment and enrollment began in December 2025, and complete T1 data from 69 participants have been collected as of February 2026. It is expected that T1 data collection will be completed by April 2026, and T2 data collection will occur between June and October 2026. Data analysis on T1 data is expected to begin in May 2026. We anticipate results to be published in fall 2027.

Exploring real-time associations between psychological and socioenvironmental factors and physical activity will provide a more comprehensive understanding of the dynamic barriers and facilitators influencing individuals' engagement in physical activity in their everyday lives. The outcomes of this work will help advance existing theories on behavioral choice and effort minimization and inform the development of decision rules for adaptive interventions that are tailored to individuals' unique and current context.