Background: Only 17% of Latinas meet national physical activity (PA) guidelines for both moderate-to-vigorous aerobic and muscle-strengthening PA. Additional health benefits are derived from the combination of aerobic and muscle-strengthening PA (vs. aerobic alone), yet there is paucity in research on muscle-strengthening activity in Latinas. The aim of this study was to examine changes in muscle-strengthening activity from baseline to 6 and 12 months in Seamos Saludables, a 12-month PA randomized controlled trial for Latinas. Methods: A secondary data analysis was conducted among 131 Latinas ages 18–65 years, who were randomized to either a PA Intervention or a Wellness Control. Self-reported muscle-strengthening exercise was measured at baseline, 6 months, and 12 months via adapted muscle-strengthening questions from the Behavioral Risk Factor Surveillance System. Results: There was a 16-minute/week difference in median minute/week of muscle-strengthening activity between Intervention and Wellness at 6 months ( SE = 7.91, p = .04) and 45-minute/week difference at 12 months ( SE = 25.80, p = .06) adjusting for baseline. Significantly more PA Intervention participants met muscle-strengthening guidelines of 2 or more days/week at 6 months versus Wellness Control participants (odds ratio [OR] = 4.29, 95% confidence interval [CI] = [1.03, 17.84]). Conclusion: Results from the current study showed that Latinas engaged in muscle-strengthening activity in an intervention that emphasized primarily aerobic PA outcomes, suggesting they may be interested in engaging in muscle-strengthening activities. Future interventions targeting both aerobic and muscle-strengthening activity could achieve greater health improvements and help more Latinas reach the full national PA guidelines. ClinicalTrials.gov Identifier. NCT01583140

UNSTRUCTURED Introduction: Latino men in the U.S. report low physical activity (PA) levels and related health conditions (e.g., diabetes, obesity). Engaging in regular PA can reduce the risk of chronic diseases and yield many health benefits; yet, there is a paucity of interventions developed exclusively for Latino men. To address the need for culturally relevant PA interventions, we developed Hombres Saludables, a 6-month Spanish-language, theory-based, tailored web and text message PA intervention for Latino men. This paper describes the study design, intervention, and evaluation methods for Hombres Saludables. Methods: Latino men ages 18-65 are randomized to either the individually-tailored PA internet intervention arm or the nutrition and wellness internet control arm. The PA intervention includes: 2 check-in phone calls, automated SMS text messages, a pedometer, a 6-month gym membership, access to a private Facebook group, and an interactive website with PA tracking, goal setting, and individually-tailored PA content. Outcomes: The primary outcome is minutes/week of moderate-to-vigorous PA (MVPA) assessed via ActiGraph GT3X+ accelerometer and 7-Day Physical Activity Recall at baseline and 6-months. Secondary outcomes will examine potential moderators (e.g., demographics, acculturation, and environmental variables) and mediators (e.g., self-efficacy, cognitive and behavioral processes of change) of treatment effects at 6-months post-randomization. Conclusions: Hombres Saludables uses an innovative, interactive web and text message-based intervention for improving PA among Latino men, an underserved population at risk of low PA and related chronic disease. If the intervention demonstrates feasibility, acceptability, and preliminary efficacy, we will refine and evaluate it in a larger randomized control trial.