Introduction: After haematopoietic stem cell transplantation (HSCT), patients often experience complications such as respiratory difficulties, fatigue and decreased quality of life. The aim of the study was to compare the effectiveness of different inspiratory muscle training (IMT) protocols on respiratory muscle strength and endurance, dyspnoea, maximal exercise capacity, diaphragmatic function, respiratory function parameters, peripheral muscle strength, fatigue, quality of life, oxidative stress parameters, muscle biomarkers and inflammatory biomarkers in HSCT recipients during the transplantation process. Method: The study will include patients between 18-65 years of age, who are able to walk and understand the instructions, who do not have orthopedic, neurological or cardiac disorders and who will undergo haematopoietic stem cell transplantation. Patients with cognitive impairments; orthopedic or neurological diseases that may affect the evaluation of physical fitness tests; patients with comorbidities such as asthma, COPD will not be included in the study. In cases where the exercise group subjects' attendance to the training protocol is interrupted for 3 sessions or more consecutively, the voluntariness to participate in the research is lost during the research process, and clinical haemodynamic instability develops in the subjects, the participant will be excluded from the study. Patients in whom exercise training is contraindicated such as acute bleeding, haemoglobin value \<5 g/dl, platelet count ≤10000 mm3, high fever (body temperature \>38◦C), severe pain, confusion, dizziness, nausea and vomiting will not be included in the exercise. It is planned as a prospective, randomised controlled and single blinded study. Triple blinding could not be performed due to the executive's evaluation and implementation of the study protocol. Patients included in the study will be randomly divided into 3 study groups of 15 people each. Stratified randomisation technique will be used. A total of 45 haematopoietic stem cell transplant patients will be included in the study. Patients will be evaluated 3 times: before exercise therapy (pre-HSCT), before and after starting the preparatory regime and after exercise therapy (post-HSCT). Primary assessment measures are dyspnoea, maximal exercise capacity, respiratory muscle strength and endurance, diaphragmatic respiration, oxidative stress parameters, inflammatory markers, muscle biomarkers, pulmonary function test. Secondary assessment measures were peripheral muscle strength, fatigue, depression, and quality of life. The research arms consisted of a total of 45(15;15;15) people in 3 groups: 'standard inspiratory muscle training group', 'functional respiratory muscle training group' and 'control group' with 15 people in each group. All patients in the control and research groups will receive inspiratory muscle training for a total of 30 minutes twice a day, every weekday during the transplantation period, starting at the end of the session in which their initial assessment was made. Functional respiratory muscle training group will perform functional exercises simultaneously with inspiratory muscle training 3 days a week (Monday-Wednesday-Friday or Tuesday-Thursday-Saturday). All exercises will be supervised by a physiotherapist. The most important originality of this study is that it is the first study to investigate the effects of functional respiratory muscle training on respiratory parameters, diaphragm function, peripheral muscle strength, maximum oxygen consumption, dyspnoea, fatigue, depression and quality of life in HSCT recipients. It is the first randomised controlled study to demonstrate the effect of inspiratory muscle training on diaphragmatic function in HSCT recipients and it is one of the rare studies in which exercise capacity will be evaluated by cardiopulmonary exercise test. It is also the first study to examine the relationship between inspiratory muscle training and muscle biomarkers and oxidative stress parameters in HSCT recipients. H0: There is no difference in the effectiveness of different inspiratory muscle training protocols on maximal exercise capacity, respiratory muscle strength, respiratory muscle endurance, diaphragmatic function, oxidative stress parameters, muscle biomarkers, inflammatory biomarkers, dyspnoea, peripheral muscle strength, quality of life, fatigue, depression in haematopoietic stem cell transplant recipients. H1: There is a difference in the effectiveness of different inspiratory muscle training protocols on maximal exercise capacity, respiratory muscle strength, respiratory muscle endurance, diaphragmatic function, oxidative stress parameters, muscle biomarkers, inflammatory biomarkers, dyspnoea, peripheral muscle strength, quality of life, fatigue, depression in haematopoietic stem cell transplant recipients.