Increasing aerobic and muscle-strengthening physical activity in Latinas via interactive web-based technology

ABSTRACT Cancer is the leading cause of death among Latinos in the U.S. While engaging in a physically active lifestyle is one of the most important modifiable behaviors for reducing cancer risk; few Latinas achieve health- enhancing levels of physical activity (PA) recommended by the National PA Guidelines, particularly for muscle-

strengthening activities (MSA). For instance, 44% of Latinas meet the national guidelines for aerobic PA but only 17% meet the full guidelines for both aerobic and MSA. While the benefits of aerobic MVPA are well established for cancer and chronic disease prevention, participating in regular MSA may be key to further

reducing cancer risk, as adherence to MSA guidelines has been associated with a 19% to 31% lower cancer mortality risk, independent of aerobic PA. There is a need for interventions promoting MSA in Latinas. However, only a select few MSA interventions have included Latinas in their sample, and none to our

knowledge, were designed exclusively for this group or addressed socio-cultural factors influencing Latinas' muscle-strengthening behaviors (e.g., perception that MSA is for men; MSA is an avoided topic in their culture and social circles; belief that women should only do certain types of MSA). Moreover, existing interventions

often involved in-person exercise programs, which can be inaccessible to many Latinas due to barriers such as lack of transportation or fear of immigration enforcement. Our research team has previously developed and tested aerobic moderate-to-vigorous PA (MVPA) interventions for Latinas that overcome barriers to in-person

programs and address PA-related socio-cultural factors. These theory-driven, individually tailored interventions have shown success at increasing aerobic MVPA among Latina women in both print and Internet-based randomized controlled trials. Thus, our web-based intervention (Pasos Hacia la Salud), in particular, provides

an ideal platform for promoting muscle-strengthening PA in this at-risk population. To address the gap in literature on muscle-strengthening PA, we recently conducted qualitative interviews with 19 Latinas to identify theory-based barriers and facilitators of muscle-strengthening PA, then developed MSA intervention materials

and are further refining for cultural appropriateness, relevance, and appeal in Latinas. In the proposed research, we will incorporate the newly developed MSA promotion materials into our existing Pasos Hacia la Salud (Pasos) web-based aerobic MVPA intervention and conduct a 12-week fully online randomized pilot trial

testing the preliminary efficacy of the newly adapted web-based aerobic plus MSA intervention for Latinas. Fifty Latina adults (i.e., aged 18-65-years) will be randomized to either the: 1) original Pasos aerobic MVPA intervention arm, or 2) a Pasos aerobic MVPA plus MSA intervention arm. Our study aims to 1) Assess the

preliminary efficacy of the aerobic and muscle-strengthening intervention for increasing MSA, and 2) Explore potential mediators and moderators of MSA. This interactive and highly disseminable approach can achieve significant health improvements in an at-risk population.