Efficacy of 24-week instability resistance training on cognitive function of older adults with probable mild cognitive impairment: A randomized, assessor-blinded, sham-controlled trial

Objective To determine the effects of instability resistance training (IRT) on the cognitive function of older adults with probable mild cognitive impairment (MCI). Methods This was assessor-blinded, randomized controlled trial which included 162 adults aged ≥65 years, physically independent and who had indicative of MCI. Participants were randomly allocated to either 24-week of twice-weekly IRT (n = 80) or active control group (n = 82). IRT group underwent resistance exercises on unstable surfaces (i.e., Balance Pad, Bosu® ball), prescribed as seven exercises in 3 sets with target zone ranging between 10–15 repetitions. The active control group performed non-structured (no progression neither complexity), low intensity functional and stretching/relaxation exercises. Cognitive outcomes Executive Function (Stroop Color Task; Digit Symbol Substitution Test; Trail Making Test Part A and B; Digit Span Memory Test; Verbal fluency test) and Memory were assessed at baseline, after 12- and 24-week. Linear mixed modeling, adjusted for sex, age, and baseline levels of each outcome, were used to determine treatment effects. Results 162 participants with a mean age of 70.4 ± 4.3 years and indicative of MCI (MoCA 20.1 ± 4.2) were included. At 24-week, the IRT group demonstrated significant improvements in executive function performance (Verbal Fluency – Letter A: +1.2 letters; 95% CI 0.2–2.2; p = 0.017; Digit Span Forward: +0.7 points; 95% CI 0.1–1.3; p = 0.010) compared with active control group. No significant between-group differences were observed in the remaining cognitive outcomes. Conclusion Our findings revealed that 24-week IRT improved executive functioning domains among older adults with probable MCI. Trial Registration RBR-9bv3dc9.