JMIR Publications

ABSTRACT

Background:

Initial evidence suggests that mindsets about the adequacy and health consequences of one’s physical activity (activity adequacy mindsets, AAMs) can shape physical activity behavior, health and wellbeing. However, it is unknown how to leverage these mindsets using wearable technology and other interventions.

Objective:

This research examined how wearable fitness trackers and meta-mindset interventions influence AAMs, affect, behavior and health.

Methods:

162 community-dwelling adults were recruited via flyers and online platforms (i.e., Craigslist, Nextdoor; final sample size after attrition/ exclusion of 45 participants). Participants received an Apple Watch to wear for 5 weeks, which was equipped with an app that recorded step count and could display a (potentially manipulated) step count on the watch face. After a baseline week of receiving no feedback about step count, participants were randomly assigned to one of four experimental groups: they received either (1) accurate step count (reference group, n = 41), 40% deflated step count (n = 40), 40% inflated step count (n = 40), or accurate step count + a web-based meta-mindset intervention teaching participants the value of adopting more positive AAMs (n = 41). Participants were blinded to condition. Outcome measures were taken in lab by an experimenter in the beginning and end of participation, and via web-based surveys in between. Longitudinal analysis examined changes within the accurate condition from baseline to treatment and compared them with changes in the deflated, inflated, and meta-mindset conditions.

Results:

Participants receiving accurate step count perceived their activity as more adequate and healthier, adopted a healthier diet, and experienced improved mental health (PROMIS-29) and aerobic capacity, but also reduced functional health (PROMIS-29) (compared to their no-step-count baseline). Participants exposed to deflated steps perceived their activity as more inadequate, ate more unhealthily and experienced more negative affect, reduced self-esteem and mental health, and increased blood pressure and heart rate (compared to participants receiving accurate steps). Inflated steps did not change AAM and most other outcomes (compared to accurate steps). Participants receiving the meta-mindset intervention experienced improved AAM, affect, functional health, and self-reported physical activity (compared to participants receiving accurate steps only). Actual step count did not change in either condition.

Conclusions:

AAMs––induced by trackers or adopted deliberately––can influence affect, behavior, and health, independent of actual physical activity. Clinical Trial: ClinicalTrials.gov Identifier NCT03939572