7 - (IOP 15) Feasibility and Acceptability of a Smartwatch-based Ecological Momentary Assessment App to Assess Affective Response During Exercise

How good or bad people feel during exercise, i.e., their affective response (AR), predicts future exercise engagement. Thus, AR may be an important mechanism to target within exercise interventions. Ecological momentary assessment (EMA) is a method used to measure participants’ in-real-time experiences such as AR during exercise. Typically, EMAs are captured by pushing prompts to participants’ smartphones. However, having to carry a phone to respond to EMAs during exercise has been described by some participants as disruptive and/or burdensome. Thus, phone-delivered EMA lacks critical acceptability and feasibility for measuring AR during exercise. A smartwatch might be a better tool to collect EMAs during exercise, given that they are designed to be worn and interacted with during activity. However, data regarding the feasibility of using smartwatches to collect EMAs during exercise is limited, and no prior studies have assessed acceptability of this method with cancer survivors.

This study is aligned with step two of the science of behavior change (SOBC) experimental medicine framework (to reliably measure key mechanisms of action underlying target behaviors). The purpose of this study was to test the feasibility and acceptability of using a smartwatch app (PHITbit) to collect EMAs during exercise. Results will be used to inform protocol refinements for an exercise intervention for breast cancer survivors.

Data were collected from stage 0-III breast cancer survivors within 5 years of completing primary treatment (NCT05868746; N=27 enrolled, n=24 downloaded the app; Mage = 60.81±11.51, 96.3% female, 96.3% White). Participants installed the PHITbit app on a study-issued Fitbit Versa 3 smartwatch and reported affective response and perceived effort during planned exercise sessions across a 10-day data collection period. Participants opened the PHITbit app when starting an exercise session and were prompted to report AR (via the Feeling Scale; -5 “very bad” to 5 “very good”) and effort (via the Rating of Perceived Exertion Scale; 0 “no effort” to 10 “max effort”) every 5 minutes up to minute 30 and then every 10 minutes up to minute 60. Participants could end the data collection session at any time by closing the PHITbit app. Feasibility was assessed via PHITbit app usage rates. Acceptability was assessed via the System Usability Scale (SUS), where a score ≥ 68 indicates high acceptability.

Twenty (83.33%) of 24 participants responded to at least three prompts in the PHITbit app during at least one exercise episode. On average, participants responded to at least one prompt in the app during 7.04 (SD = 6.58) exercise episodes over the 10-day recording period. Participants used the PHITbit app during more than 80% of reported exercise episodes. Average SUS score was 82.86 (SD = 15.46), indicating high acceptability.

Results suggest delivering EMAs via smartwatch during exercise was both highly feasible and acceptable for our sample of breast cancer survivors. By offering a less burdensome method to measure AR in response to exercise, smartwatch-based EMA data collection could support future intervention work attempting to address step three of the SOBC framework (influence mechanisms).