Vicia Faba Peptides and Resistance Training in the Elderly

• Vicia faba L.-derived peptides (Dietary supplement): Participants assigned to the experimental intervention will receive 2.5 g/day of Vicia faba L.-derived peptides for four weeks. The supplement will be administered once daily as a powder using a measuring scoop containing the prescribed dose and diluted in 300 mL of drinking water. Participants will consume the supplement at home every day, including weekends. Containers will be returned at the end of the intervention to assess adherence.
• Placebo (Dietary supplement): Participants assigned to the placebo intervention will receive silicified microcrystalline cellulose once daily for four weeks. The placebo will be administered as a powder diluted in 300 mL of drinking water and will be standardized to match the mode of presentation and administration of the experimental supplement. Participants will consume the placebo at home every day, including weekends. Containers will be returned at the end of the intervention to assess adherence.
• Supervised Resistance Training (Behavioral): All participants will complete a supervised resistance training program for four weeks, with three sessions per week performed on non-consecutive days. The program will target the major muscle groups of the upper and lower limbs using resistance-training equipment, free weights, and other available implements. Exercise prescription will be individualized according to each participant's functional capacity, previous experience, and clinical limitations. Training loads will be progressively adjusted throughout the intervention according to individual progress and exercise tolerance.

Primary outcomes

• Change in Fat-Free Mass (kg) [Baseline and after 4 weeks of intervention]: Change in fat-free mass following the 4-week intervention. Fat-free mass will be assessed using multifrequency bioelectrical impedance analysis (InBody 570) under standardized pre-assessment conditions. Fat-free mass will be expressed in kilograms (kg).

Secondary outcomes

• Change in Handgrip Strength (kgf) [Baseline and after 4 weeks of intervention]: Change in handgrip strength. Handgrip strength will be assessed using a hydraulic hand dynamometer. Three measurements will be performed for each hand, with approximately 30 seconds of rest between attempts. The mean of the three measurements will be used for analysis, and results will be expressed in kilograms-force (kgf).
• Change in Maximal Voluntary Isometric Contraction and Muscle Power during Knee Extension and Flexion [Baseline and after 4 weeks of intervention]: Maximal Voluntary Isometric Contraction (MVIC) and Muscle Power during Knee Extension and Flexion will be assessed using a Biodex Multi-Joint System dynamometer. Muscle power during concentric knee flexion and extension will be evaluated at angular velocities of 60°/s and 180°/s. MVIC will be measured across 3 attempts, with a 1-minute resting interval, with the knee flexed at 90°. Outcome for MVIC will include peak torque (N·m), while outcome for muscle power will consist in total work done.
• Change in Lower-Limb Strength Endurance (repetitions) [Baseline and after 4 weeks of intervention]: Lower-limb strength endurance will be assessed using the 30-Second Chair Stand Test. The outcome will include the total number of complete sit-to-stand repetitions performed within 30 seconds.
• Change in Upper-Limb Muscle Power (meters) [Baseline and after 4 weeks of intervention]: Upper-limb muscle power will be assessed using the Seated Medicine Ball Throw Test. With the bench standing in 45°, participants will throw a medicine ball (3 kg for men, 2 kg for women) forward from a seated position using a chest-pass movement. Throwing distance, in meters, will be measured from the starting point to the point where the ball first contacts the floor.
• Change in Dynamic Balance [Baseline and after 4 weeks of intervention]: Dynamic balance will be assessed using the Instrumented Timed Up and Go (iTUG) test with the Baiobit inertial sensor system. Outcomes will include total completion time (in seconds) and kinematic parameters related to the different phases of the task.
• Change in Self-Reported Functional Disability [Baseline and after 4 weeks of intervention]: Self-reported functional disability will be assessed using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), an instrument developed by the World Health Organization for the cross-sectional measurement of functional disability, applicable to any health condition. Scores will be calculated according to the World Health Organization technical manual using the simple scoring method, in which raw scores for each domain are summed and subsequently transformed into a 0-100 point scale, where higher values indicate a greater level of disability.
• Change in body fat percentage [Baseline and after 4 weeks of intervention]: Change in body fat percentage, in percent, will be assessed using multifrequency bioelectrical impedance analysis (InBody 570) under standardized pre-assessment conditions.
• Change in Vastus Lateralis and Rectus Femoris Muscle Thickness (cm) [Baseline and after 4 weeks of intervention]: Change in Vastus lateralis and Rectus Femoris Muscle Thickness will be assessed by ultrasonography of the dominant limb at 30 and 70% of the distance from the greater trochanter of the femur and the lateral femoral condyle. Muscle thickness will be measured in centimeters.
• Change in Physical Frailty Phenotype [Baseline and after 4 weeks of intervention]: Physical frailty will be assessed using the Fried Frailty Phenotype, which includes five components: unintentional weight loss, self-reported exhaustion, reduced handgrip strength, slow walking speed, and low physical activity level. Participants will be classified as non-frail, pre-frail, or frail.
• Change in Intensity of Depressive Symptoms [Baseline and after 4 weeks of intervention]: Change in the intensity of depressive symptoms will be assessed using the Beck Depression Inventory - Second Edition (BDI-II), a self-report instrument widely used to measure the severity of depressive symptoms and validated for the Brazilian population. The questionnaire consists of 21 items, each containing four options graded from 0 to 3 points, reflecting the increasing intensity of symptoms over the past two weeks. The total score ranges from 0 to 63 points, with higher scores indicating greater severity of depressive symptoms. To interpret the results, the following conventionally used cut-off points will be adopted: 0-13 (minimal), 14-19 (mild), 20-28 (moderate), and 29-63 (severe).
• Change in Quality of Life [Baseline and after 4 weeks of intervention]: Change in Quality of life will be assessed using the World Health Organization Quality of Life-OLD (WHOQOL-OLD). The instrument consists of 24 questions distributed across six facets: Sensory Functioning, Autonomy, Past/Present/Future Activities, Social Participation, Death and Dying, and Intimacy. Each facet comprises four questions, resulting in a multidimensional assessment of quality of life related to aging. Responses are recorded on a five-point Likert scale (ranging from 1 to 5) based on the degree of intensity, satisfaction, frequency, or agreement associated with each question. Initially, the values obtained for each facet will be summed, followed by the transformation of the scores onto a 0-100 scale, allowing for better interpretation and comparison of results across participants and different assessment time points. On this transformed scale, higher values will indicate a better perception of quality of life.

Sex: All, ages: 60 Years to any, accepts healthy volunteers

Inclusion Criteria:

* Age 60 years or older;
* Classification as physically active or physically inactive according to the criteria established in the study;
* Clinical and functional conditions compatible with participation in the assessments and resistance training program;
* Availability to participate in the activities scheduled throughout the intervention period;
* Provision of written informed consent.

Exclusion Criteria:

* Musculoskeletal injuries or conditions that prevent or compromise the safe performance of physical assessments or resistance training;
* Acute or uncontrolled clinical or psychiatric conditions that may compromise participant safety or adherence to the study protocol;
* Neurodegenerative diseases associated with relevant functional or cognitive impairment;
* Use of restrictive diets that may interfere with dietary intake or body composition outcomes;
* Use of medications specifically intended for weight loss;
* Regular use of ergogenic supplements with the potential to interfere with the muscular or metabolic adaptations investigated in the study.

• Vitor S Painelli, Dr, Principal investigator, Centro Universitário Cesumar