Benefits of Strength Training in Informal Caregivers of Patients With Alzheimer's Disease

N/ANot Yet RecruitingNCT07388186

University of Salamanca62 enrolled

Overview

Informal caregivers of people with Alzheimer's disease experience high physical and psychological burden, increasing their risk of frailty, anxiety, and caregiver burnout. This randomized controlled trial aims to evaluate the effectiveness of a combined strength training and progressive muscle relaxation program compared with progressive muscle relaxation alone. The intervention will last 10 weeks, with assessments conducted at baseline, post-intervention, and at a 3-month follow-up. Primary outcomes include frailty, anxiety, and caregiver burden.

Alzheimer's disease is associated with long-term caregiving demands that expose informal caregivers to sustained physical and psychological stress. This chronic exposure may contribute to functional decline, increased vulnerability to frailty, and reduced overall well-being, highlighting the need for accessible, non-pharmacological interventions targeting caregiver health. The present study adopts a parallel-group randomized controlled design in which participants are allocated to one of two intervention arms. One group will participate in structured progressive muscle relaxation sessions, while the other will receive a combined intervention integrating functional strength training with progressive muscle relaxation. The intervention protocol has been designed to be feasible, low-cost, and easily implementable in community and clinical settings. Assessments will be conducted at multiple time points to examine changes in physical performance and psychological status over time. Standardized performance-based measures and validated self-report instruments will be used to capture functional and psychosocial outcomes, allowing for a comprehensive evaluation of the intervention effects across short- and medium-term follow-up periods.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Interventions

Progressive Muscle RelaxationBEHAVIORAL

Progressive muscle relaxation will be delivered in weekly supervised sessions over a 10-week period. Each session will last approximately 45 minutes and will include diaphragmatic breathing, systematic muscle contraction and relaxation following Jacobson's technique, controlled breathing exercises, and a brief cooldown period. The intervention will be administered by a trained physiotherapist in a group setting.

Functional Strength TrainingBEHAVIORAL

Functional strength training will be delivered in weekly supervised sessions over a 10-week period. Sessions will last approximately 45 minutes and will focus on improving upper limb, lower limb, and core muscle strength using progressive resistance exercises. Training intensity will be gradually increased according to participant tolerance and performance. All sessions will be supervised by a trained physiotherapist.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Adults aged 18 years or older * Informal caregivers of a person with Alzheimer's disease * Providing regular care for at least 10 hours per week * Ability to attend intervention sessions * Ability to understand and follow instructions * Provision of written informed consent Exclusion Criteria: * Acute illness or medical conditions contraindicating participation in strength exercise * Participation in structured exercise programs that may interfere with study outcomes * Severe or uncontrolled psychiatric disorders * Physical limitations preventing completion of functional assessments

Outcomes

Primary Outcomes

Frailty

Frailty will be assessed using the Short Physical Performance Battery (SPPB) and handgrip strength measured with a hand dynamometer. The SPPB includes balance, gait speed, and lower-limb strength components. The score is obtained by summing the results of three performance-based tests: balance, gait speed over 4 meters, and the five-times sit-to-stand chair test. The total score ranges from 0 to 12 points, where 0 represents the worst performance and 12 the best performance. Lower scores (generally \<10) indicate frailty and increased risk of falls. Performance is classified as follows: 0-3 (disabled), 4-6 (frail), 7-9 (prefrail), and 10-12 (independent). Handgrip strength will be measured using a hand dynamometer, and the absolute grip strength value will be recorded. The Fried frailty phenotype includes handgrip strength (dynamometry) as one of the five key criteria for identifying frailty in older adults. Cut-off values indicative of muscle weakness, adjusted for sex and body mass

Time frame: Baseline, 3-month follow-up and immediately after completion of the intervention (at 10 weeks).

Secondary Outcomes

Anxiety

Anxiety symptoms will be assessed using the Hamilton Anxiety Rating Scale (HAM-A), a validated clinician-rated questionnaire evaluating psychological and somatic anxiety symptoms. HAM-A is scored on a scale of 0 (not present) to 4 (severe), with a total score range of 0-56, where \<17 indicates mild severity, 18-24 mild to moderate severity and 25-30 moderate to severe.

Time frame: Baseline, 3-month follow-up and immediately after completion of the intervention (at 10 weeks)

Caregiver burden

Caregiver burden will be assessed using the Zarit Burden Interview (ZBI), a validated self-report questionnaire measuring perceived burden in informal caregivers. The total score is calculated as the sum of all items, with a possible range from 22 to 110. Each item is rated using a 5-point Likert-type scale, with response options ranging from "never" to "almost always", scored from 1 to 5.