The current study aimed to develop and assess an easy-to-use, highly accessible mobile and web-based application intervention to reduce sedentary behavior and increase physical activity in the hope of reducing the side effects of treatment and improving quality of life for the 13,000 or more prostate cancer survivors who are prescribed ADT each year in Canada. The study was conducted in two phases, where Phase one was focused on finding out about the attitudes and perceptions of sedentary behavior and the use of mobile applications among prostate cancer survivors using semi-structured interviews. Together with professional experts and a group of men who were diagnosed with prostate cancer, we developed RiseForTx - an application that is used on a smartphone or tablet to reduce time spent in, and to change patterns of, sedentary behaviour each day (Phase two). Part of the intervention was also focused on increasing daily steps to improve physical activity. We tested the intervention to examine (i) how the application works, (ii) if prostate cancer survivors like it and use it; and (iii) if sedentary behaviour and physical activity can reduce the impact of the side effects for treatment and improve quality of life among men on ADT.

In the first 10 days following recruitment, participants met with the research coordinator and were provided with an accelerometer (GT3X) and completed self-report baseline measures. Provided along with the RiseTx application is the Jawbone, which is a wrist-worn device that can assess activity patterns throughout the day and provide sensory alerts to stand after prolonged sitting (i.e., ≥30 minutes of sedentary time). The intervention consisted of five phases following initial data collection, including a baseline phase (weeks 1-2) where participants self-monitored their typical leisure time PA (i.e., step counts) and were asked to 'sync' their Jawbone with the RiseTx application to view their daily progress and steps. This daily self-monitoring process continued over the remaining intervention period. Based on a previously tested ramped step count approach that focuses on increasing walking by an extra 1000 daily steps over a set period, participants attempted to increase daily steps by 1000 over the average of their baseline week. Phases I-III involved progressive release of self-regulatory strategies (e.g., action planning) on the application and targeted changes in both sitting time (and breaks in sitting time) and step counts. Phase I (weeks 3-4) focused on increasing low intensity, incidental movement, through the use of an alerting device, and the Jawbone (reminder to break SED). At this time, an additional +1000 daily step increment was set above baseline. Phase II (weeks 5-6) targeted shorter planned PA (of up to 10 mins) by having participants form action plans on the application for both reducing SED and increasing PA. An additional +1000 daily step increment was set above Phase I. Phase III (weeks 7-8) focused on promoting longer, moderate intensity PA (>10 min), where participants used the application to form coping plans for barriers to reducing sitting time or engaging in PA. An additional +1000 daily step increment was set above Phase II step target. A 4-week consolidation phase (Phase IV and V; weeks 9-12) followed, where participants received weekly reminders that encouraged them to continue to use the RiseTx application to practice combining the different self-regulatory strategies learned in Phases I-III. Following the intervention, there was a 12-week maintenance period (weeks 13-24) where participants no longer received weekly self-regulatory practice reminders, yet still had access to the application.

Inclusion Criteria:

• ≥ 18 years of age
• Men with localized or asymptomatic metastatic primary prostate cancer (Stage I-III)
• Currently receiving ADT (continuous and/or intermittent) for at least 6 months
• Active e-mail address to access the intervention website
• Proficient in English
• Physically inactive (< 150 minutes of moderate-intensity PA/week)
• No uncontrolled co-morbidities
• Medical clearance from the primary healthcare provider