The Effect of a Mixed-type Intradialytic Exercise Training Program on Body Composition, Functional Capacity, and Muscle Oxygenation of the Upper and Lower Limbs in Hemodialysis Patients

Chronic kidney disease (CKD) is a progressive clinical condition that affects a growing number of people worldwide. While advances in haemodialysis techniques have led to notable improvements in survival rates and the quality of life (QoL) of patients with CKD (PwCKD), significant complications persist, primarily associated with chronic uremia. These include skeletal muscle atrophy, reduced muscular strength and diminished functional capacity.

Recent studies support the role of systematic exercise as a non-pharmacological strategy to reduce issues and improve musculoskeletal function among haemodialysis patients. Specifically, intradialytic exercise gained ground due to its efficiency in time utilization and elimination of transport burden. Nevertheless, most of the intradialytic exercise programs implement aerobic exercise and there is a lack of studies investigating combined strength and aerobic exercise modalities, which may offer more comprehensive physiological benefits.

The aim of the randomized controlled trial (RCT) is to examine whether a 6-month combined aerobic and resistance exercise program, implemented during haemodialysis sessions, could affect body composition, muscle oxygenation of the lower and upper extremities, and functional capacity of patients that underwent haemodialysis.

Forty patients will be randomly allocated into two groups: Group A (Exercise Group) will undergo 3 sessions per week of an intradialytic exercise program for 6 months and Group B (Control Group) will receive the usual care without participating in organized exercise programs.

Prior to the group random allocation, part of our assessments at baseline and after 6 (Evaluation A') will include demographics and clinical history, body composition analysis via bioelectrical impedance analysis, muscle oxygenation monitoring of the vastus lateralis and biceps brachii muscles at rest and during exercise using near-infrated spectroscopy (NIRS) technology. Functional capacity will be assessed through validated tests: Six-minute walk test (6MWT), 30-second sit-to-stand test, five-repetition sit-to-stand test (5STS), handgrip strength, 4-meter gait speed test. Additionally, we will use questionnaires assessing physical activity using International Physical Activity Questionnaire (IPAQ), depression using Beck Depression Inventory (BDI), stress using Generalized Anxiety Disorder 7-item scale(GAD-7) and the QoL using Kidney Disease Quality of Life Short Form(KDQOL-SF) of people that underwent dialysis.

Study Overview

• Status: Active, not recruiting
• Conditions: Chronic Kidney Disease; Functional Capacity; Haemodialysis; Intradialytic Exercise
• Intervention / Treatment: Other: EXERCISE INTERVENTION

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

Contacts and Locations

Study Locations

• Greece
  • Thessaloniki, Greece, 57001
    • Sports Medicine Laboratory, Aristotle University of Thessaloniki

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age > 18 and <80 years, either gender
• Confirmed diagnosis
• Patients undergoing maintenance hemodialysis therapy for at least 6 months.

Exclusion Criteria:

• Acute myocardial infraction
• Severe valvular disease
• Potentially malignant arrhythmias
• Unstable angina
• Hospitalized patients
• Uncontrolled diabetes mellitus
• Uncontrolled hypertension
• Neurological, or orthopedic limitations/non-ambulant status
• Cognitive or psychiatric disorders
• Poor regulation of comorbidities
• Already participating in organized exercise programs
• Current pregnancy
• Inability/unwillingness to give informed consent

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Exercise; Exercise Group, 6- month combined aerobic and strength exercise	Other: EXERCISE INTERVENTION; Patients randomly assigned to this group will be invited to attend a 6 month exercise program. The 6-month exercise intervention will be conducted three times per week during the first two hours of each hemodialysis session at the 2nd Nephrology Clinic at AHEPA University Hospital. Each session will begin with a warm-up phase, followed by aerobic exercise using bedside-adapted cycle ergometers. Exercise duration will initially be set at 30 minutes and progressively increased to 60 minutes, performed at moderate intensity (12-13 on the 6-20 Borg Rating of Perceived Exertion scale). After the first month, resistance training will be gradually introduced, initially using body weight and subsequently incorporating elastic resistance bands. Each session will conclude with a cool-down period.
No Intervention: Usual care; Control Group, 6- month without participating in organized exercise activities, no intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical and demographic characteristics		Baseline
Clinical and demographic characteristics		6-month
Muscle oxygenation Assessment-MOXY	Measurement of vastus lateralis and biceps brachii muscle oxygenation at rest and during exercise using near-infrared spectroscopy (NIRS) devices (Moxy 1408, Fortiori Design LLC, Minnesota, USA; Moxy 2136, Idiag AG, Fehraltorf, Switzerland).	Baseline
Body composition analysis	Bioelectrical impedance analysis (Bodystat QuadScan 4000).	Baseline
Body composition analysis	Bioelectrical impedance analysis (Bodystat QuadScan 4000).	6-month
Six minute walk test	Aerobic capacity	Baseline
Six minute walk test	Aerobic capacity	6-month
JAMAR SMART Hand Dynamometer	Handgrip Strength	Baseline
JAMAR SMART Hand Dynamometer	Handgrip Strength	6- month
30-second Sit-to-Stand Test	Lower limb functional capacity	Baseline
30-second Sit-to-Stand Test	Lower limb functional capacity	6- month
Five-Repetition Sit-to-Stand Test (5STS)	Lower limb functional capacity	Baseline
Five-Repetition Sit-to-Stand Test (5STS)	Lower limb functional capacity	6- month
4-Meter Gait Speed Test		Baseline
4-Meter Gait Speed Test		6- month
Baseline leg dynamometer		Baseline
Muscle oxygenation Assessment-MOXY	Measurement of vastus lateralis and biceps brachii muscle oxygenation at rest and during exercise using near-infrared spectroscopy (NIRS) devices (Moxy 1408, Fortiori Design LLC, Minnesota, USA; Moxy 2136, Idiag AG, Fehraltorf, Switzerland).	6-month
International Physical Activity Questionnaire (IPAQ).	Assessment of Physical Activity (PA) Levels (MET-min/week). Using the IPAQ scoring protocol, participants classified into three PA categories: low (<600 MET-min/week), moderate, and high (active) (≥3000 MET-min/week or vigorous PA ≥1500 MET-min/week). Higher scores indicate more physically active patients.	Baseline
International Physical Activity Questionnaire (IPAQ).	Assessment of Physical Activity (PA) Levels (MET-min/week). Using the IPAQ scoring protocol, participants classified into three PA categories: low (<600 MET-min/week), moderate, and high (active) (≥3000 MET-min/week or vigorous PA ≥1500 MET-min/week). Higher scores indicate more physically active patients.	6- month
Beck Depression Inventory (BDI)	Assessment of depressive symptoms. Total score ranges from 0 to 63. Each item is scored 0-3, where higher scores indicate more severe symptoms. Typical interpretations are: 0-13 (minimal), 14-19 (mild), 20-28 (moderate), and 29-63 (severe).	Baseline
Beck Depression Inventory (BDI)	Assessment of depressive symptoms. Total score ranges from 0 to 63. Each item is scored 0-3, where higher scores indicate more severe symptoms. Typical interpretations are: 0-13 (minimal), 14-19 (mild), 20-28 (moderate), and 29-63 (severe).	6- month
Generalized Anxiety Disorder-7 scale (GAD-7).	Assessment of anxiety symptoms. The Generalized Anxiety Disorder-7 scale (GAD-7) is a 7-item self-report questionnaire assessing anxiety symptoms over the past 2 weeks, with a total score range of 0-21 (items scored 0-3). Severity categories are 0-4 minimal, 5-9 mild, 10-14 moderate, and 15-21 severe; Higher scores indicate more severe anxiety symptoms.	Baseline
Generalized Anxiety Disorder-7 scale (GAD-7).	Assessment of anxiety symptoms. The Generalized Anxiety Disorder-7 scale (GAD-7) is a 7-item self-report questionnaire assessing anxiety symptoms over the past 2 weeks, with a total score range of 0-21 (items scored 0-3). Severity categories are 0-4 minimal, 5-9 mild, 10-14 moderate, and 15-21 severe; Higher scores indicate more severe anxiety symptoms.	6- month
Kidney Disease Quality of Life Short Form (KDQOL-SF™)	Assessment of health-related quality of life. The Kidney Disease Quality of Life Short Form (KDQOL-SF™) assesses kidney disease-specific and general health. Domain scores range from 0-100 scale (minimum 0; maximum 100). Higher scores indicate better quality of life.	Baseline
Kidney Disease Quality of Life Short Form (KDQOL-SF™)	Assessment of health-related quality of life. The Kidney Disease Quality of Life Short Form (KDQOL-SF™) assesses kidney disease-specific and general health. Domain scores range from 0-100 scale (minimum 0; maximum 100). Higher scores indicate better quality of life.	6- month
Baseline leg dynamometer		6- month

Collaborators and Investigators

• Sponsor: Aristotle University Of Thessaloniki
• Investigators: Study Chair: Evangelia Kouidi, Professor, Sports Medicine Laboratory, School of Physical Education and Sports Science, Aristotle University of Thessaloniki, Greece

Study record dates

Study Major Dates

• Study Start (Actual): June 27, 2025
• Primary Completion (Actual): January 27, 2026
• Study Completion (Estimated): April 7, 2026

Study Registration Dates

• First Submitted: February 17, 2026
• First Submitted That Met QC Criteria: February 17, 2026
• First Posted (Actual): February 23, 2026

Study Record Updates

• Last Update Posted (Actual): March 2, 2026
• Last Update Submitted That Met QC Criteria: February 27, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Pathologic Processes; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Chronic Disease; Disease Attributes; Renal Insufficiency; Pathological Conditions, Signs and Symptoms; Renal Insufficiency, Chronic
• Other Study ID Numbers: 121/2022

Drug and device information, study documents

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