Implementing multi-site behavioral intervention trials to study Alzheimer's disease (AD) has many unique challenges, leading to substantial variations in delivered intervention doses and cognitive findings. These issues can be addressed by the IMplementation Framework fOr Behavioral and LIfestyLe Interventions In AlZheimer's DiseasE (MOBILIZE), which was developed to guide the design and implementation of behavioral interventions in AD. Building on the person-centered principle, MOBILIZE includes three implementation outcomes with corresponding team processes: (1) screening (processes), (2) intervention adherence (processes), and (3) safety (processes). This study systematically evaluated MOBILIZE implementation outcomes of the 3-site aerobic exercise and cognitive training (ACT) Trial (recruitment started on 4/1/2018 and last follow-up on 7/17/2024). Outcomes included time in screening phases, intervention adherence (attendance and intervention dose adherence, and safety [adverse events]). Sample (n = 146) was 73.8 ± 5.7 years in age and 23.4 ± 2.1 on Montreal Cognitive Assessment score, with 48.0% female and 91.8% White. The median days of screening-to-enrollment averaged 98 days. Attendance was 76.7 ± 28.6%. Adherence to 100% exercise session dose and 100% cognitive session dose was 71.7 ± 30.8% and 51.5 ± 26.2%, respectively. There were 10 study-related adverse events. MOBILIZE helped the ACT Trial achieve high intervention attendance and safety and may be important for early-stage trials in AD.Trial registration The ACT Trial is registered at clinicaltrials.gov (NCT03313895). Registered 15 July 2017, https://clinicaltrials.gov/study/NCT03313895 .