The Impact of Aerobic Exercise Program on Immunosenescence Institutionalized Older Adults

The Impact of Aerobic Exercise Program on Immunosenescence in Institutionalized Older Adults: a Study Protocol for Randomized Controlled Trials

Background: Immunosenescence is an age-related decline in immune function, associated with chronic low-grade inflammation, increased morbidity, and functional impairment in older adults. Aerobic exercise has been proposed as an effective non-pharmacological strategy to counteract these alterations; however, evidence from randomized-controlled trials (RCTs), particularly in institutionalized elderly populations, remains scarce and methodologically limited.

Objective: This study protocol aims to investigate the effects of short- and medium-term aerobic exercise programs on immunosenescence in institutionalized older adults, as well as to analyze the impact of a detraining period and a subsequent reintervention.

Methods: A stratified RCT will be conducted with institutionalized adults aged ≥60 years, randomly allocated to an aerobic exercise group or a control group. The intervention consists of a supervised 12-week moderate-intensity aerobic exercise program (three sessions/week), followed by a 4-week detraining period and a 4-week reintervention. Assessments will be performed at five time points. Primary outcomes include immunological and analytical parameters assessed by spectral flow cytometry and multiplex cytokine analysis. Secondary outcomes include anthropometry, functional capacity, hemodynamic parameters, heart rate variability, and psychological indicators.

Expected Results: Aerobic exercise is expected to induce favorable immunological adaptations, partially reverse immunosenescence, and improve functional and psychosocial outcomes.

Study Overview

• Status: Not yet recruiting
• Conditions: Aging; Immunosenescence
• Intervention / Treatment: Behavioral: Aerobic exercise program

Detailed Description

This investigation will be based on a stratified randomized intervention. Participants will initially be stratified according to clinical conditions. Within each stratum, a 1:1 randomization will be performed to the experimental group (AERG) and control group (CG) using software SPSS. The randomization sequence will be generated using variable-size permuted blocks to ensure a balance in the number of participants in each group and reduce the risk of allocation predictability. Randomization will be performed by a researcher external to the data collection and intervention implementation process. The randomization will be stored in an encrypted file until the start of the intervention, ensuring allocation concealment.

An aerobic exercise program (12 weeks) will be implemented, followed by a detraining period (4 weeks) and the implementation of a second intervention (4 weeks). Primary outcomes include analysis of analytical parameters and cellular assessment. Secondary outcomes include anthropometric analysis, functional capacity, hemodynamic parameters, and psychological parameters. All participants will be assessed at five distinct time points, as shown in Figure 1: before the intervention (T0), at 6 weeks (T6) and at 12 weeks (T12) of intervention, after the detraining period (T16), and after the second intervention (T20).

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Carlos M Farinha, Carlos Farinha, Dr.; Phone Number: +351924167929; Email: cmnfarinha@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion criteria:

Participants must be aged 60 years or older and institutionalized. Studying institutionalised older adults ensures greater uniformity in diet, daily routines, behaviours, and environmental exposures, thereby minimising the impact of external factors other than the exercise intervention.

Exclusion criteria:

Participants will be excluded if they have acute conditions that may affect their immune or inflammatory responses. These conditions include recent trauma or surgery (within the previous six months), recent blood transfusions (within the previous month), acute infections (such as respiratory, gastrointestinal, or urinary infections), recent vaccinations, and the use of medications that may interfere with immune responses (such as immunomodulators, systemic corticosteroids, methotrexate, and biologics).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Aerobic Exercise Group; Group of participants who will take part in a supervised aerobic exercise program.	Behavioral: Aerobic exercise program; Supervised moderate-intensity aerobic exercise program based on ACSM and WHO recommendations. Sessions will be delivered 3 times per week for 60 minutes, fully supervised by a certified exercise professional. Each session includes: (1) 5-10 min warm-up (joint mobility and light walking), (2) 30-50 min continuous aerobic exercise (primarily walking) targeting large muscle groups at 50-70% HRmax (Borg RPE 5-7), and (3) 5-10 min active recovery and static stretching. Intensity and progression will follow ACSM guidance, starting at light-to-moderate intensity and increasing continuous aerobic duration by ~5 min/week during the first 4 weeks, with subsequent individualized adjustments according to participants' adaptations. Adherence will be tracked via attendance logs, with ≥80% session attendance required for adequate compliance. Safety will be ensured through continuous monitoring for adverse events (e.g., chest pain, palpitations, abnormal dyspnea) with immediate session interruption an
No Intervention: Control Group; A group of participants who will maintain their usual routines, without any systematic practice of physical exercise.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sodium	Serum sodium concentration measured from peripheral blood samples. Unit of measure: mmol/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Potassium	Serum potassium concentration measured from peripheral blood samples. Unit of measure: mmol/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Chloride	Serum chloride concentration measured from peripheral blood samples. Unit of measure: mmol/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Calcium	Total serum calcium concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Phosphorus	Serum phosphorus concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Magnesium	Serum magnesium concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Aspartate aminotransferase (AST)	Serum AST activity measured from peripheral blood samples. Unit of measure: U/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Alanine aminotransferase (ALT)	Serum ALT activity measured from peripheral blood samples. Unit of measure: U/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Gamma-glutamyl transferase (GGT)	Serum gamma-glutamyl transferase activity measured from peripheral blood samples. Unit of measure: U/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Total bilirubin	Total bilirubin concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Direct bilirubin	Direct bilirubin concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Alkaline phosphatase	Serum alkaline phosphatase activity measured from peripheral blood samples. Unit of measure: U/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Lactate dehydrogenase (LDH)	Serum lactate dehydrogenase activity measured from peripheral blood samples. Unit of measure: U/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Total cholesterol	Total cholesterol concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
HDL cholesterol	High-density lipoprotein cholesterol concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
LDL cholesterol	Low-density lipoprotein cholesterol concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Triglycerides	Serum triglyceride concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Amylase	Serum amylase activity measured from peripheral blood samples. Unit of measure: U/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Urea	Serum urea concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Creatinine	Serum creatinine concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Uric acid	Serum uric acid concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Total proteins	Total serum protein concentration measured from peripheral blood samples. Unit of measure: g/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Albumin	Serum albumin concentration measured from peripheral blood samples. Unit of measure: g/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Glucose	Fasting blood glucose concentration measured from peripheral blood samples. Unit of measure: mg/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Glycated haemoglobin (HbA1c)	Glycated haemoglobin measured from peripheral blood samples. Unit of measure: %	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Creatine kinase (CK)	Serum creatine kinase activity measured from peripheral blood samples. Unit of measure: U/L	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Red blood cell count	Red blood cell count measured from peripheral blood samples. Unit of measure: 10^6/µL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Haemoglobin	Haemoglobin concentration measured from peripheral blood samples. Unit of measure: g/dL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Haematocrit	Haematocrit measured from peripheral blood samples. Unit of measure: %	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
White blood cell count	White blood cell count measured from peripheral blood samples. Unit of measure: 10^3/µL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Platelet count	Platelet count measured from peripheral blood samples. Unit of measure: 10^3/µL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Natural killer (NK) cell count	Natural killer cell count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL and %	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
CD3+ T cell count	CD3+ T lymphocyte count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
CD4+ T cell count	CD4+ T lymphocyte count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
CD8+ T cell count	CD8+ T lymphocyte count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
B cell count	B lymphocyte count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Interleukin-6 (IL-6)	Plasma IL-6 concentration measured using multiplex technology from peripheral blood samples. Unit of measure: pg/mL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Tumour necrosis factor-alpha (TNF-α)	Plasma TNF-α concentration measured using multiplex technology from peripheral blood samples. Unit of measure: pg/mL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Interleukin-10 (IL-10)	Plasma IL-10 concentration measured using multiplex technology from peripheral blood samples. Unit of measure: pg/mL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Interleukin-1 beta (IL-1β)	Plasma IL-1β concentration measured using multiplex technology from peripheral blood samples. Unit of measure: pg/mL	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Height	Height measured using a portable stadiometer. Unit of measure: m	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Weight	Body weight measured using a portable scale. Unit of measure: kg	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Body mass index (BMI)	Body mass index calculated from height and body weight. Unit of measure: kg/m²	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Visceral fat	Visceral fat measured using a portable scale. Unit of measure: score	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Body fat percentage	Body fat percentage measured using a portable scale. Unit of measure: %	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Muscle mass percentage	Muscle mass percentage measured using a portable scale. Unit of measure: %	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Waist circumference	Waist circumference measured using a retractable fiberglass tape measure. Unit of measure: cm	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Arm circumference	Arm circumference measured using a retractable fiberglass tape measure. Unit of measure: cm	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Leg circumference	Leg circumference measured using a retractable fiberglass tape measure. Unit of measure: cm	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
30-Second Chair Stand Test	Number of full stands completed in 30 seconds from a seated position, used to assess lower body strength. Unit of measure: repetitions	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
30-Second Arm Curl Test	Number of arm curls completed in 30 seconds, used to assess upper body strength. Unit of measure: repetitions	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
6-Minute Walk Test	Distance covered in 6 minutes while walking, used to assess cardiorespiratory endurance. Unit of measure: meters	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Chair Sit-and-Reach Test	Distance between the extended fingers and the tip of the toe in the seated sit-and-reach position, used to assess lower body flexibility. Unit of measure: cm	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Back Scratch Test	Distance between the middle fingers when reaching one hand over the shoulder and the other up the middle of the back, used to assess upper body flexibility. Unit of measure: cm	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
8-Foot Up-and-Go Test	Time taken to rise from a chair, walk 8 feet, turn, and return to the seated position, used to assess agility and dynamic balance. Unit of measure: seconds	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Heart rate (HR)	Resting heart rate measured using an automatic digital sphygmomanometer. The average of three measurements will be recorded. Unit of measure: beats per minute (bpm)	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Systolic blood pressure (SBP)	Resting systolic blood pressure measured using an automatic digital sphygmomanometer. The average of three measurements will be recorded. Unit of measure: mmHg	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Diastolic blood pressure (DBP)	Resting diastolic blood pressure measured using an automatic digital sphygmomanometer. The average of three measurements will be recorded. Unit of measure: mmHg	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Heart rate variability (HRV)	Heart rate variability assessed during a 10-minute resting test using a heart rate monitor in a calm, quiet, and dimly lit environment. Data will be transferred from the Polar Flow Web Service for analysis. Unit of measure: ms	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Perceived stress	Perceived stress assessed using the Perceived Stress Scale (PSS). Unit of measure: score	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
General health status	Health-related quality of life assessed using the EuroQol (EQ-5D). Unit of measure: score	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Life satisfaction	Satisfaction with life assessed using the Satisfaction With Life Scale (SWLS). Unit of measure: score	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Positive affect	Positive affect assessed using the Positive and Negative Affect Schedule (PANAS). Unit of measure: score	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)
Negative affect	Negative affect assessed using the Positive and Negative Affect Schedule (PANAS). Unit of measure: score	Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20)

Collaborators and Investigators

• Sponsor: Instituto Politécnico de Castelo Branco

Study record dates

Study Major Dates

• Study Start (Estimated): March 2, 2026
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): October 30, 2026

Study Registration Dates

• First Submitted: February 25, 2026
• First Submitted That Met QC Criteria: March 12, 2026
• First Posted (Actual): March 17, 2026

Study Record Updates

• Last Update Posted (Actual): March 17, 2026
• Last Update Submitted That Met QC Criteria: March 12, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Elderly; Aerobic exercise; Aging; Immunosenescence; Immune system; Institutionalized
• Other Study ID Numbers: IPCB-ESE

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No