Respiratory Muscle Training and Walking Exercise in Women Recovering From COVID-19 Pneumonia (RECOVID-EX)

Investigation of the Effects of Respiratory Muscle Training and Walking Exercises on Some Blood and Respiratory Parameters in Patients Recovering From COVID-19 Lung Inflammation

This experimental study was designed to investigate the effects of respiratory muscle training and walking exercise on selected blood, respiratory, functional, dyspnea, sleep quality, and quality-of-life outcomes in women who had recovered from COVID-19-related lung inflammation/pneumonia. The study included women aged 20 to 45 years who had experienced COVID-19 with pneumonia, reported dyspnea, and had reduced quality of life.

A total of 80 female participants were divided into four groups: respiratory muscle training plus walking exercise, respiratory muscle training alone, walking exercise alone, and a control group, with 20 participants in each group. Measurements were performed before and after the intervention period. The assessments included pulmonary function testing, maximal inspiratory pressure, the 6-minute walk test, the modified Borg scale for dyspnea, the Nottingham Health Profile, the Pittsburgh Sleep Quality Index, and selected blood parameters. The study aimed to determine whether respiratory muscle training, walking exercise, or their combination could improve respiratory function, inspiratory muscle strength, functional capacity, dyspnea, sleep quality, quality of life, and blood-related parameters in this population.

Study Overview

• Status: Completed
• Conditions: COVID-19 Pneumonia; Respiratory Symptoms
• Intervention / Treatment: Behavioral: Respiratory Muscle Training; Behavioral: Walking Exercise

Detailed Description

This was a single-blind, experimental, pretest-posttest intervention study conducted in adult women who had recovered from COVID-19-related pneumonia and continued to experience dyspnea during the post-discharge period. Participants were recruited from routine post-discharge follow-up settings and were informed about the study procedures before participation. Written informed consent was obtained from all participants before any study-related procedures were performed.

Before the start of the intervention period, participants completed a familiarization session and trial measurements to reduce learning-related variability during the actual assessments. Baseline measurements were then performed, and participants were allocated into four study groups according to their pretest results: respiratory muscle training, respiratory muscle training plus walking exercise, walking exercise, and control.

The respiratory muscle training intervention was performed for 8 weeks using a pressure-threshold respiratory muscle training device. The training load was set at 50% of each participant's maximal inspiratory pressure. Participants in the respiratory muscle training group performed the intervention 5 days per week, twice daily, with 30 breaths in each session. Respiratory muscle strength was reassessed weekly, and the training load was updated according to changes in maximal inspiratory pressure.

The combined intervention group completed the same respiratory muscle training protocol in addition to a structured walking exercise program. The walking exercise consisted of 40 minutes of walking, 3 days per week, either outdoors or on a treadmill, at a pace of approximately 4 to 6 km/hour. Exercise intensity was prescribed using a target heart rate approach corresponding to 40% intensity and was monitored during the sessions with an optical heart rate sensor. Before walking exercise, participants completed a 10-minute warm-up and stretching routine for the upper and lower extremities.

The walking exercise group completed only the structured walking program using the same frequency, duration, intensity, and monitoring procedures as the walking component of the combined intervention group. The control group did not receive a structured exercise intervention and continued their usual daily routine during the study period.

Study data were collected using individual participant forms. These forms included health history, medication use, smoking status, previous physical activity status, basic physical characteristics, and all pre- and post-intervention measurement values. The intervention process and exercise sessions were monitored throughout the study period. Measurements were repeated after the 8-week intervention period to evaluate changes within and between the study groups.

• Study Type: Interventional
• Enrollment (Actual): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Çorum
    • Çorum, Çorum, Turkey (Türkiye), 19100
      • Hitit University Çorum Erol Olçok Training and Research Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Female participants aged 20 to 45 years
• History of COVID-19-related pneumonia
• Presence of dyspnea after COVID-19
• Modified Borg dyspnea score between 1 and 7 after the 6-minute walk test
• Resting oxygen saturation between 90% and 95%
• Incomplete resolution of COVID-19-related lesions on chest radiography
• Voluntary agreement to participate in the study
• Signed written informed consent form

Exclusion Criteria:

• Modified Borg dyspnea score between 0 and 1
• Modified Borg dyspnea score greater than 7
• History of chronic obstructive pulmonary disease, heart failure, or pulmonary fibrosis causing dyspnea before COVID-19 pneumonia
• Upper abdominal or thoracic surgery within the previous 3 months
• Cancer
• Pregnancy
• Presence of another disease contributing to dyspnea in addition to COVID-19-related dyspnea
• Cardiovascular, musculoskeletal, or nervous system involvement related to COVID-19
• Mental disorder or mental instability
• Language barrier preventing understanding of Turkish
• Refusal to participate or withdrawal from the study at any stage
• History of being a competitive athlete
• Lack of voluntary participation or refusal to sign the written informed consent form

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Respiratory Muscle Training; Participants in this arm received respiratory muscle training for 8 weeks using a pressure-threshold respiratory muscle training device. The training intensity was set at 50% of each participant's maximal inspiratory pressure and was updated according to weekly changes in respiratory muscle strength.	Behavioral: Respiratory Muscle Training; Participants performed respiratory muscle training for 8 weeks using a pressure-threshold respiratory muscle training device. The training load was set at 50% of each participant's maximal inspiratory pressure. Training was performed 5 days per week, twice daily, with 30 breaths in each session. Maximal inspiratory pressure was reassessed weekly, and the training load was adjusted according to the updated value.
Experimental: Respiratory Muscle Training Plus Walking Exercise; Participants in this arm received respiratory muscle training in addition to a structured walking exercise program for 8 weeks. The walking exercise was performed 3 days per week for 40 minutes at 40% intensity based on the target heart rate method, either outdoors or on a treadmill. Exercise intensity was monitored using an optical heart rate sensor.	Behavioral: Respiratory Muscle Training; Participants performed respiratory muscle training for 8 weeks using a pressure-threshold respiratory muscle training device. The training load was set at 50% of each participant's maximal inspiratory pressure. Training was performed 5 days per week, twice daily, with 30 breaths in each session. Maximal inspiratory pressure was reassessed weekly, and the training load was adjusted according to the updated value.; Behavioral: Walking Exercise; Participants performed a structured walking exercise program for 8 weeks. Walking exercise was performed 3 days per week for 40 minutes at an intensity corresponding to 40% based on the target heart rate method. Walking was performed either outdoors or on a treadmill at an approximate pace of 4 to 6 km/hour. Exercise intensity was monitored using a Polar Verity Sense optical heart rate sensor. Before walking, participants completed a 10-minute warm-up and stretching protocol for the upper and lower extremities.
Experimental: Walking Exercise; Participants in this arm performed structured walking exercise for 8 weeks. Walking was performed 3 days per week for 40 minutes at a pace of approximately 4-6 km/hour and at 40% intensity based on the target heart rate method. Exercise intensity was monitored during the sessions using an optical heart rate sensor.	Behavioral: Walking Exercise; Participants performed a structured walking exercise program for 8 weeks. Walking exercise was performed 3 days per week for 40 minutes at an intensity corresponding to 40% based on the target heart rate method. Walking was performed either outdoors or on a treadmill at an approximate pace of 4 to 6 km/hour. Exercise intensity was monitored using a Polar Verity Sense optical heart rate sensor. Before walking, participants completed a 10-minute warm-up and stretching protocol for the upper and lower extremities.
No Intervention: Control; Participants in this arm did not receive any structured exercise intervention and continued their usual daily routine during the study period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Maximal Inspiratory Pressure	Change in maximal inspiratory pressure from baseline to post-intervention. Maximal inspiratory pressure was used to assess inspiratory respiratory muscle strength.	Baseline and Week 8

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Forced Vital Capacity	Change in forced vital capacity from baseline to Week 8. Forced vital capacity was assessed using pulmonary function testing and reported in liters.	Baseline and Week 8
Change in Forced Expiratory Volume in 1 Second	Change in forced expiratory volume in 1 second from baseline to Week 8. Forced expiratory volume in 1 second was assessed using pulmonary function testing and reported in liters.	Baseline and Week 8
Change in Peak Inspiratory Flow	Change in peak inspiratory flow from baseline to Week 8. Peak inspiratory flow was assessed as a respiratory function parameter and reported in liters per second.	Baseline and Week 8
Change in Inspiratory Volume	Change in inspiratory volume from baseline to Week 8. Inspiratory volume was assessed as a respiratory function parameter and reported in liters.	Baseline and Week 8
Change in 6-Minute Walk Test Distance	Change in functional exercise capacity from baseline to post-intervention, assessed by the 6-minute walk test.	Baseline and Week 8
Change in Modified Borg Dyspnea Score	Change in perceived dyspnea from baseline to post-intervention, assessed using the modified Borg scale.	Baseline and Week 8
Change in Nottingham Health Profile Score	Change in health-related quality of life from baseline to post-intervention, assessed using the Nottingham Health Profile.	Baseline and Week 8
Change in Pittsburgh Sleep Quality Index Score	Change in sleep quality from baseline to post-intervention, assessed using the Pittsburgh Sleep Quality Index.	Baseline and Week 8
Change in Blood Parameters	Change in selected blood parameters from baseline to post-intervention, including leukocyte count, erythrocyte count, and hemoglobin.	Baseline and Week 8

Collaborators and Investigators

• Sponsor: Hitit University

Publications and helpful links

General Publications

• Tosun MI. Investigation of the Effects of Respiratory Muscle Training and Walking Exercises on Some Blood and Respiratory Parameters in Patients Recovered From COVID-19 Lung Inflammation. Doctoral dissertation. Hitit University, Graduate School, Department of Physical Education and Sports; 2023.

Study record dates

Study Major Dates

• Study Start (Actual): January 16, 2023
• Primary Completion (Actual): May 26, 2023
• Study Completion (Actual): May 29, 2023

Study Registration Dates

• First Submitted: June 11, 2026
• First Submitted That Met QC Criteria: June 15, 2026
• First Posted (Actual): June 18, 2026

Study Record Updates

• Last Update Posted (Actual): June 18, 2026
• Last Update Submitted That Met QC Criteria: June 15, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: COVID-19; Dyspnea; Walking Exercise; Respiratory Muscle Training; Maximal Inspiratory Pressure; Post-COVID-19 Recovery
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Lung Diseases; Respiration Disorders; Pneumonia, Viral; Pneumonia; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; COVID-19; Dyspnea; Signs and Symptoms, Respiratory; Therapeutics; Mind-Body Therapies; Complementary Therapies; Exercise Movement Techniques; Physical Therapy Modalities; Breathing Exercises
• Other Study ID Numbers: 2022-98

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared publicly because the dataset contains personal health-related information collected from female participants who had recovered from COVID-19-related pneumonia. The data were collected as part of a doctoral thesis study and were analyzed in de-identified form for the purposes of the study.

Drug and device information, study documents

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