Comparison of Functional Inspiratory Muscle Training and Combined Exercise Training in Individuals With Type 2 Diabetes

Participants allocated to the combined exercise training group will receive an eight-week online exercise program supervised by a physiotherapist. The program will include aerobic, resistance, and balance exercises aimed at improving functional capacity, peripheral muscle strength, and postural balance. Exercise intensity and progression will be individualized according to each participant's functional capacity and exercise tolerance.

Participants allocated to the control group will continue their usual medical care during the eight-week study period. They will receive general education on type 2 diabetes management, the importance of physical activity, and healthy lifestyle habits. However, they will not participate in a structured exercise program or receive functional inspiratory muscle training or combined exercise training as part of the study.

Participants allocated to the functional inspiratory muscle training group will receive an eight-week online inspiratory muscle training program using an inspiratory muscle training device. Training will be performed at 30-40% of maximal inspiratory pressure (MIP), for approximately 30 minutes per day, seven days per week. One session per week will be supervised online by a physiotherapist. Training intensity will be adjusted according to individual MIP measurements and exercise tolerance.

Functional capacity will be assessed using the Six-Minute Walk Test (6MWT). Participants will be instructed to walk as far as possible within six minutes. The total distance walked will be recorded in meters. Higher distances indicate better functional capacity.

Fatigue will be assessed using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) Scale. The scale consists of 13 items, with a total score ranging from 0 to 52. Higher scores indicate lower fatigue levels and better fatigue-related quality of life.

Dynamic balance and functional mobility will be assessed using the Timed Up and Go (TUG) Test. Participants will stand up from a chair, walk three meters, turn around, return to the chair, and sit down. The completion time will be recorded in seconds. Lower values indicate better performance.

Balance confidence will be assessed using the Activities-specific Balance Confidence (ABC) Scale. Participants will rate their confidence in maintaining balance during daily activities. Scores range from 0% to 100%, with higher scores indicating greater balance confidence.

Peripheral muscle strength will be assessed using a handheld dynamometer (KFORCE). Muscle strength measurements will be performed bilaterally for the selected upper- and lower-extremity muscle groups using standardized testing positions. Results will be recorded in the measurement units provided by the device. Higher values indicate greater muscle strength.

Expiratory muscle strength will be assessed by measuring maximal expiratory pressure (MEP) with a respiratory pressure-measuring device. Results will be expressed in cmH2O. Higher values indicate greater expiratory muscle strength.

Diabetes-related quality of life will be assessed using the Diabetes Quality of Life Brief Clinical Inventory (DQoL-BCI). This 15-item questionnaire evaluates the impact of diabetes on daily life, satisfaction with diabetes management, and diabetes-related concerns. Changes in quality of life will be assessed before and after the eight-week intervention.

Instrumental activities of daily living will be assessed using the Lawton-Brody Instrumental Activities of Daily Living Scale. The scale evaluates independence in daily activities such as telephone use, shopping, food preparation, housekeeping, laundry, transportation, medication management, and financial management. Higher scores indicate greater independence in instrumental activities of daily living.

Lower extremity functional performance will be assessed using the 30-Second Sit-to-Stand Test (30STS). Participants will be instructed to stand up fully from a seated position and sit down as many times as possible within 30 seconds, without using their arms for assistance. The total number of correctly completed repetitions will be recorded. Higher repetition counts indicate better lower extremity functional performance.

Waist circumference will be measured using a non-elastic measuring tape and recorded in centimeters (cm). Measurements will be performed using a standardized anatomical landmark and measurement procedure. Changes in waist circumference will be evaluated from baseline to the end of the eight-week intervention.