Rationale and design of a pilot randomized controlled trial to increase moderate-to-vigorous physical activity in preadolescent Latina girls and their mothers.

Background: Hispanic/Latina girls have a low prevalence of moderate-intensity physical activity (PA) compared to their male counterparts and non-Hispanic White girls. Mothers influence their children's activity levels by creating and supporting PA opportunities, modeling PA, and reinforcing children's efforts to be physically active. The trial will evaluate a mother-daughter intervention to promote PA and examine potential mechanisms of change including mothers' PA, parenting regarding PA, and mother-daughter communication.

Method: This randomized controlled trial examines the feasibility, acceptability, and impact of a 12-week intervention promoting PA in preadolescent Latina girls in San Diego County, CA. Participants (n = 90 dyads) are randomized to the PA intervention or to a control group that receive an abbreviated version of the intervention. The intervention was informed by Social Cognitive Theory and Family Systems Theory and emphasize family-level factors to promote PA using an actor-partner model. Mothers and daughters attend weekly 90-min sessions in English or in Spanish via Zoom video conferencing, supported by facilitator follow-ups and WhatsApp supportive chat group for mothers. Objective (accelerometer) and self-report measures at baseline, 3 months, and 6 months capture the frequency and intensity of PA and correlates and predictors of PA. We also examine the impact of the intervention on the bidirectional influence of mother-daughter PA.

Implications: The findings from the Conmigo trial will form the basis of a randomized controlled community trial and will move the field forward in identifying targets of change in preventing chronic disease risk in Hispanic/Latino communities.