The Study of Mental and Resistance Training (SMART) Study-Resistance Training and/or Cognitive Training in Mild Cognitive Impairment: A Randomized, Double-Blind, Double-Sham Controlled Trial

Background: Mild cognitive impairment (MCI) increases dementia risk with no pharmacologic treatment available. Methods: The Study of Mental and Resistance Training was a randomized, double-blind, double-sham controlled trial of adults with MCI. Participants were randomized to 2 supervised interventions: active or sham physical training (high intensity progressive resistance training vs seated calisthenics) plus active or sham cognitive training (computerized, multidomain cognitive training vs watching videos/quizzes), 2-3days/week for 6months with 18-month follow-up. Primary outcomes were global cognitive function (Alzheimer's Disease Assessment Scale-cognitive subscale; ADAS-Cog) and functional independence (Bayer Activities of Daily Living). Secondary outcomes included executive function, memory, and speed/attention tests, and cognitive domain scores. Results: One hundred adults with MCI [70.1 (6.7) years; 68% women] were enrolled and analyzed. Resistance training significantly improved the primary outcome ADAS-Cog; [relative effect size (95% confidence interval)-0.33 (-0.73, 0.06); P<.05] at 6months and executive function (Wechsler Adult Intelligence Scale Matrices; P=.016) across 18months. Normal ADAS-Cog scores occurred in 48% (24/49) after resistance training vs 27% (14/51) without resistance training [. P<.03; odds ratio (95% confidence interval) 3.50 (1.18, 10.48)]. Cognitive training only attenuated decline in Memory Domain at 6months (. P<.02). Resistance training 18-month benefit was 74% higher (. P=.02) for Executive Domain compared with combined training [z-score change=0.42 (0.22, 0.63) resistance training vs 0.11 (-0.60, 0.28) combined] and 48% higher (. P<.04) for Global Domain [z-score change=.0.45 (0.29, 0.61) resistance training vs 0.23 (0.10, 0.36) combined]. Conclusions: Resistance training significantly improved global cognitive function, with maintenance of executive and global benefits over 18months