mHealth to support resistance training using outdoor gyms: the ecofit hybrid type 3 implementation-effectiveness trial.

Abstract

There is a need to scale up effective physical activity interventions among the general population, particularly those incorporating resistance training. Ecofit is a community-based, multicomponent intervention promoting resistance and aerobic physical activity through smartphone technology, the outdoor built environment, and social support. This study aimed to scale up ecofit by comparing Low versus Moderate implementation support on the reach (outdoor gym use) of ecofit within two large regional municipalities. A hybrid type 3 implementation-effectiveness trial was conducted across two large municipalities in eastern Australia. Outdoor gyms (n = 18) were randomized to Low (ecofit app only) or Moderate [ecofit app, QR (quick response) codes on equipment, face-to-face workout sessions] implementation support. The primary outcome of "reach" was defined as the baseline-adjusted difference in the number of outdoor gym users (i.e. adults using outdoor gym equipment for resistance training) between groups. Reach was measured at baseline and 3-month follow-up using a modified System for Observing Play and Recreation in Communities tool, with blinded assessors observing community members perceived to be ≥18 years [categorized as Adults (aged 18-59) or Seniors (aged ≥60)]. Secondary outcomes included app uptake, dose received, implementation fidelity, and acceptability, feasibility, and dose-satisfaction regarding the app and guided sessions. There was no significant difference in people using outdoor gym equipment for resistance training between Low and Moderate support groups at 3-month follow-up [incidence rate ratio (IRR) = 1.68, 95% CI: 0.96-2.94]. Among adults (aged 18-59), the Moderate support group showed significantly higher outdoor gym use at follow-up (IRR = 1.83, 95% CI: 1.01-3.31) compared to the Low support group. Over 6 months, 1273 users registered for the app, completing 503 workouts, 62% of which occurred indoors. Ecofit shows promise for promoting resistance training, particularly among adults. Broader marketing and enhanced engagement strategies may be required to increase outdoor gym use and sustain participation over time. Outdoor gyms are increasingly installed in parks to encourage free, accessible exercise, yet they are often underused. We implemented the ecofit intervention, a free mobile app designed to help people use outdoor gyms for resistance and aerobic exercise, across two large regional municipalities in Australia. The app includes predesigned workouts, instructional videos, customizable options, and self-monitoring tools. We compared two levels of implementation support: nine gyms received Low support (ecofit app only), while another nine received Moderate support [ecofit app, QR (quick response) codes on equipment, and three cost-free group workouts led by an exercise professional]. The main aim was to compare the number of people using outdoor gyms receiving Low and Moderate support at baseline and 3 months. There was no significant difference in overall outdoor gym use between the Low and Moderate support groups. However, more adults under 60 used outdoor gyms with Moderate support compared to Low support at follow-up. Over 6 months, more than 1200 people registered for the app and completed 503 workouts. Users found the app easy to use and motivating, though many preferred private settings for exercise. Ecofit shows promise for promoting resistance training using outdoor gyms. Future studies should incorporate broader marketing and collaborate with municipal councils and local government agencies to improve engagement and accessibility.