Type 2 Diabetes Mellitus and Downhill Aerobic Exercise Training

The Effect of Downhill Walking Training on Functional Capacity, Peripheral Muscle Strength, and Cardiovascular Responses in Individuals With Type 2 Diabetes Mellitus

The purpose of this study is to compare the effects of an 8-week supervised downhill walking training program, prescribed based on the 6-minute walk test, on functional capacity, peripheral muscle strength, and cardiovascular responses in individuals with type 2 diabetes mellitus, as compared to a level walking training program.

Participants who agree to take part in the study will be randomly assigned to either the downhill or the level-ground walking group. Both groups will undergo a 6-minute walk test (6MWT) at the beginning of the study, and participants will then undergo an 8-week walking training program-conducted twice a week on a treadmill under the supervision of a physical therapist-in which their walking speed is determined based on their average speed during the 6MWT and gradually increased, with the duration of the sessions also being extended.

Participants will do the following:

• They will participate in walking training sessions at a center twice a week for 8 weeks, under the supervision of a physical therapist.
• Once a week for 8 weeks, they will walk the same distance they walked with their supervisor that week as a homework assignment.
• They will come to the facility where they conducted their exercise sessions for evaluations at the beginning of the program and after the 8th week.

Study Overview

• Status: Recruiting
• Conditions: Walking; Aerobic Exercise; Diabete Type 2
• Intervention / Treatment: Other: Downhill Aerobic Walking Training; Other: Home exercise session; Other: Level Aerobic Walking Training

• Study Type: Interventional
• Enrollment (Estimated): 34
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Meryem Bektaş Karakuş; Phone Number: +90216 500 41 95; Email: meryem.bektas@acibadem.edu.tr

Study Locations

• Turkey (Türkiye)
  • Maltepe
    • Istanbul, Maltepe, Turkey (Türkiye)
      • Recruiting
      • Bezmialem Vakıf University Dragos Hospital
      • Contact: Yasin Baki Baydaş, M.D.; Phone Number: +90216 251 65 65; Email: ybaydas@bezmialem.edu.tr

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Have been diagnosed with Type 2 diabetes mellitus according to the American Diabetes Association (ADA) diagnostic criteria
• Be able to walk independently and be physically capable of walking on a treadmill
• Have no acute cardiovascular, neurological, or orthopedic conditions that would prevent participation in the exercise program
• No major changes to antidiabetic or cardiometabolic treatments within the last 3 months
• To be under regular follow-up and in a stable clinical condition
• To have been informed about the study and to provide written informed consent

Exclusion Criteria:

• Patients with severe peripheral neuropathy or a lack of protective sensation
• Lower extremity amputation
• Diabetic foot ulcer or the presence of severe skin lesions that impair walking
• Proliferative diabetic retinopathy or advanced retinopathy that could pose a risk of complications during exercise
• Severe diabetic nephropathy (eGFR <30 mL/min/1.73 m² or macroalbuminuria >300 mg/g)
• Uncontrolled hypertension (systolic blood pressure >200 mmHg and/or diastolic blood pressure >110 mmHg)
• Fasting blood glucose level >250 mg/dL with signs of ketosis
• Unstable angina pectoris, a history of myocardial infarction within the past 6 months, or a history of clinically significant severe arrhythmia
• Advanced heart failure (NYHA Class III-IV)
• Having a chronic respiratory disease
• Having participated in a regular exercise, sports, or physical therapy program within the past 6 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Downhill Walking	Other: Downhill Aerobic Walking Training; This involves performing a progressive aerobic exercise program-prescribed based on the results of a 6-minute walk test-twice a week for 8 weeks, at a constant 10-degree downhill, under the supervision of a physical therapist.; Other: Home exercise session; It involves assigning the distance walked during that week's exercise session-conducted under the supervision of a physical therapist-as homework to be walked at home on one day of the same week.
Active Comparator: Level Walking	Other: Home exercise session; It involves assigning the distance walked during that week's exercise session-conducted under the supervision of a physical therapist-as homework to be walked at home on one day of the same week.; Other: Level Aerobic Walking Training; This involves performing a progressive aerobic exercise program-prescribed based on the results of a 6-minute walk test-twice a week for 8 weeks, at a constant 0-degree (i.e., level) slope, under the supervision of a physical therapist.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
6-Minute Walk Test (6MWT)	The 6DYT is a walking test used to assess a participant's submaximal exercise capacity, during which the participant walks for six minutes at a self-determined pace. The patient walks as far as possible along a 30-meter corridor for six minutes. The total distance walked during the test will be recorded in meters as the primary outcome measure.	From baseline to the end of treatment at 8 weeks
Measurement of Peripheral Muscle Strength	Muscle strength measurements for hip extension, knee extension, knee flexion, and ankle plantar flexion will be performed using a handheld dynamometer. A dynamometer is a device that enables more quantitative measurements; the person conducting the test holds it in their hand to perform manual muscle testing. Different body segments have different pads. The muscles will be properly positioned and assessed. For each muscle group, measurements will be performed 3 to 5 times on both the right and left extremities, and the peak force will be recorded for each muscle group. Results will be recorded in Newtons.	From baseline to the end of treatment at 8 weeks
Heart Rate Variability (HRV) - Root Mean Square of Successive Differences (RMSSD)	Heart Rate Variability (HRV) analysis will be conducted to assess participants' autonomic nervous system responses and cardiovascular adaptability. A high-precision Polar H10 (Polar Electro Oy, Kempele, Finland) heart rate chest strap will be used for data collection. After participants rest for 5 minutes in a supine (on their back) position in a quiet environment, 5-minute short-term R-R interval recordings will be taken. The collected data will be analyzed using the Kubios HRV (v1.7.13, Kubios Oy, Kuopio, Finland) mobile app. The software's automatic artifact correction algorithm will be used to remove signal noise. The RMSSD values will be recorded in milliseconds (ms) as a key indicator of parasympathetic activity.	From baseline to the end of treatment at 8 weeks
Heart Rate Variability (HRV) - Standard Deviation of NN Intervals (SDNN)	Heart Rate Variability (HRV) analysis will be conducted to assess participants' autonomic nervous system responses and cardiovascular adaptability. A high-precision Polar H10 (Polar Electro Oy, Kempele, Finland) heart rate chest strap will be used for data collection. After participants rest for 5 minutes in a supine (on their back) position in a quiet environment, 5-minute short-term R-R interval recordings will be taken. The collected data will be analyzed using the Kubios HRV (v1.7.13, Kubios Oy, Kuopio, Finland) mobile app. The software's automatic artifact correction algorithm will be used to remove signal noise. The SDNN values will be recorded in milliseconds (ms) to reflect overall autonomic variability.	From baseline to the end of treatment at 8 weeks
Heart Rate Variability (HRV) - Mean RR Interval	Heart Rate Variability (HRV) analysis will be conducted to assess participants' autonomic nervous system responses and cardiovascular adaptability. A high-precision Polar H10 (Polar Electro Oy, Kempele, Finland) heart rate chest strap will be used for data collection. After participants rest for 5 minutes in a supine (on their back) position in a quiet environment, 5-minute short-term R-R interval recordings will be taken. The collected data will be analyzed using the Kubios HRV (v1.7.13, Kubios Oy, Kuopio, Finland) mobile app. The software's automatic artifact correction algorithm will be used to remove signal noise. The Mean RR values will be recorded in milliseconds (ms) to indicate the average time between heartbeats.	From baseline to the end of treatment at 8 weeks
Heart Rate Variability (HRV) - LF/HF Ratio	Heart Rate Variability (HRV) analysis will be conducted to assess participants' autonomic nervous system responses and cardiovascular adaptability. A high-precision Polar H10 (Polar Electro Oy, Kempele, Finland) heart rate chest strap will be used for data collection. After participants rest for 5 minutes in a supine (on their back) position in a quiet environment, 5-minute short-term R-R interval recordings will be taken. The collected data will be analyzed using the Kubios HRV (v1.7.13, Kubios Oy, Kuopio, Finland) mobile app. The software's automatic artifact correction algorithm will be used to remove signal noise. The LF/HF ratio will be recorded as a dimensionless value summarizing the sympathovagal balance.	From baseline to the end of treatment at 8 weeks
Fatigue Severity Scale (FSS)	The Fatigue Severity Scale is a 9-item measure that assesses the severity of fatigue and how it affects a person's activities. Participants respond to each item on a Likert scale ranging from 1: "I strongly disagree" to 7: "I strongly agree." The total score on the scale ranges from a minimum of 9 to a maximum of 63. Higher scores indicate more severe fatigue and greater impairment. The use of this scale is recommended for assessing fatigue in patients with type 2 diabetes.	From baseline to the end of treatment at 8 weeks
Blood Test Results: Glycated Hemoglobin (HbA1c)	HbA1c levels will be measured to assess participants' long-term glycemic control and the metabolic effects of the exercise training. The blood sample will be ordered by the attending physician and analyzed using standard laboratory methods. Results will be reported as a percentage (%).	From baseline to the end of treatment at 8 weeks
Blood Test Results: Fasting Blood Glucose (FBG)	Fasting blood glucose levels will be measured to assess participants' current metabolic status. The blood sample will be ordered by the attending physician after an overnight fast and analyzed using standard laboratory methods. Results will be reported in milligrams per deciliter (mg/dL).	From baseline to the end of treatment at 8 weeks
Lipid Profile: Low-Density Lipoprotein (LDL) Cholesterol	LDL cholesterol levels will be measured for the purposes of cardiovascular risk management and monitoring metabolic adaptation. The blood sample will be ordered by the attending physician and analyzed using standard laboratory methods. Results will be reported in milligrams per deciliter (mg/dL).	From baseline to the end of treatment at 8 weeks
Lipid Profile: High-Density Lipoprotein (HDL) Cholesterol	HDL cholesterol levels will be measured for the purposes of cardiovascular risk management and monitoring metabolic adaptation. The blood sample will be ordered by the attending physician and analyzed using standard laboratory methods. Results will be reported in milligrams per deciliter (mg/dL).	From baseline to the end of treatment at 8 weeks
Lipid Profile: Triglycerides	Triglyceride levels will be measured for the purposes of cardiovascular risk management and monitoring metabolic adaptation. The blood sample will be ordered by the attending physician and analyzed using standard laboratory methods. Results will be reported in milligrams per deciliter (mg/dL).	From baseline to the end of treatment at 8 weeks

Collaborators and Investigators

• Sponsor: Acibadem University
• Collaborators: Bezmialem Vakif University

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: June 30, 2026
• First Submitted That Met QC Criteria: July 7, 2026
• First Posted (Actual): July 9, 2026

Study Record Updates

• Last Update Posted (Actual): July 9, 2026
• Last Update Submitted That Met QC Criteria: July 7, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes Mellitus, Type 2
• Other Study ID Numbers: 2026-06/254

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