Effects of Resistance and Dual-Task Training on Physical, Oculomotor, and Executive Functions in Older Adults With MCI

Overview

The goal of this clinical trial is to determine the effect of a combined therapeutic intervention program with anaerobic exercises (resistance exercises) and dual tasks on the physical, oculomotor, and executive functions of older adults with mild cognitive impairment. The main questions it aims to answer are: • How effective will a therapeutic intervention program combining resistance exercises with dual tasks be in improving the physical, oculomotor, and executive functions of older adults with mild cognitive impairment living in the community? Researchers will compare the effectiveness of a resistance exercise training program combined with dual tasks versus a resistance-only exercise training program to see if it improves the physical, oculomotor, and executive functions of older adults with mild cognitive impairment Participants Will: * Receive resistance exercises, resistance exercises combined with dual tasks. or the standard health care. The intervention programs will consist of 3 weekly sessions over 8 weeks. * Before the start and after the completion of the programs, they will be evaluated using a battery of tests. This includes sociodemographic and general health background, physical fitness tests, as well as assessments of executive functions and oculomotor Saccadic movements and anti-saccadic error. * be required to sign a consent form.

A randomized clinical trial will be conducted with two experimental groups and one control group. The target population will be older adults with mild cognitive impairment living in the communities of Arica (Chile) and Valencia (Spain). All participants must score between 10 and 25 points on the Montreal Cognitive Assessment (MoCA). The sample size was calculated using statistical software, based on mean differences reported in prior studies on training and dual tasks in older adults. A minimum of 11 participants per group was established, adjusted for a 20% dropout rate, a significance level of 0.01, and a statistical power of 0.9. In each city, 33 participants (men and women in a 1:1 ratio) will be recruited. Random distribution by gender will assign participants to three groups: EGR: Resistance exercises only. EGRD: Resistance exercises combined with dual tasks (cognitive tasks). CG: Control group, receiving standard health care during the study and, upon completion, the best-evaluated therapeutic intervention. Procedure The study will last 12 weeks: two weeks for baseline measurements (pre-test), eight weeks for training protocols, and two weeks for final measurements (post-test). Evaluations will include sociodemographic and health data, functional physical condition tests, executive function assessments, and saccadic and anti-saccadic eye movement measures. Interventions will be conducted at the physiotherapy faculties of the participating universities, supervised by experienced professionals blinded to group allocation. Participants will be asked not to engage in physical exercise outside the study protocols during evaluation weeks. Hypotheses Primary: The combined intervention of resistance exercises and dual tasks is more effective than isolated resistance training in improving physical, executive, and oculomotor functions in older adults with mild cognitive impairment. Secondary: The combined intervention produces greater improvements in executive function tasks (Stroop Test, Corsi Block-Tapping Test, Trail Making Test) compared to resistance training alone. Intervention Program The intervention will last eight weeks, with three weekly sessions (20-24 sessions total). Each resistance training session will last one hour, divided into: Warm-up: Joint mobility and basic movements; Resistance training: Exercises with external load; Cool-down: Breathing exercises and stretching. Exercises will target flexor and extensor groups of the elbow and knee, including bilateral leg press, unilateral knee extensions, and bilateral elbow flexion/extension. Three sets of eight repetitions will be performed for each muscle group. Training intensity will begin at 60% of one-repetition maximum (1RM) and progress to 80% by week 7, adjusted every two weeks based on new strength evaluations and perceived exertion. The combined group (EGRD) will follow the same physical protocol, incorporating memory and arithmetic tasks during exercise execution. Assessment Instruments Functional physical condition: Timed Up and Go Test (TUG), Short Physical Performance Battery (SPPB), and grip strength measured with a hydraulic dynamometer. Executive functions: Inhibitory control: Stroop Test, with three conditions (word, color, word-color); Working memory: Corsi Block-Tapping Test (CBTT), assessing visuo-spatial memory sequences; Cognitive flexibility: Trail Making Test (TMT-A and TMT-B), evaluating speed, attention, and alternation. Oculomotor function: Electrooculography (EOG) will record saccadic and anti-saccadic movements using surface electrodes and controlled visual stimuli. Statistical Analysis Population data will be presented as means for continuous variables and prevalence for categorical variables, with 95% confidence intervals. Inferential analyses will consider normality and homoscedasticity to determine parametric or non-parametric tests. A blinded researcher will conduct all analyses using IBM SPSS version 27.