Cluster Randomized Controlled Trial to Promote Physical Activity Among Low-resourced Mothers in New York City: Protocol for the Free Time for Wellness (FT4W) Effectiveness Trial.

Physical inactivity is particularly prevalent in women of low socioeconomic position (SEP) (60% are inactive), suggesting that there are structural barriers to being physically active. This study will test the effectiveness of an intervention to increase physical activity among mothers of low SEP, where there is high risk of chronic disease and significant potential to make an impact on these health disparities.

This study comprises a 3-arm parallel cluster randomized controlled trial with low-resourced mothers living in New York City. The study team will randomize fitness class sites (clusters) into Arm A (contact control), receipt of free weekly fitness classes; Arm B, receipt of free childcare combined with free weekly fitness classes; and Arm C, receipt of free childcare combined with free weekly fitness classes and, plus peer support activities. Over two years the study team will recruit eight waves totaling 630 participants into 21 fitness classes. Physical activity is the primary outcome measured using accelerometers, a self-reported questionnaire, and attendance data. Secondary outcomes (e.g., health status) and mediators/moderators (e.g., social support and cohesion) will be assessed with a baseline and follow-up questionnaire. Ethnographic methods will be used to examine how intersecting forms of social inequality shape women's experiences of physical activity and to understand how real-world conditions shape the intervention implementation. The intention-to-treat analysis will employ linear mixed-effects models (LMM) to assess the main intervention effects on physical activity outcomes and other secondary outcomes.