Recovery after lung transplantation may be challenging after a long stay in the intensive care unit or hospital after surgery. The structure and function of the diaphragm (most important breathing muscle) is very important for good recovery after surgery. Training this muscle before surgery may provide "extra reserve" to cope with the stresses after surgery. Rehabilitation guidelines suggest that inspiratory muscle training (IMT) combined with standard whole-body exercises prior to major surgery can reduce post-operative complications and expedite recovery. In major thoracic surgery or organ transplantation, the mechanisms and clinical benefits of IMT have not been well established. The lung transplant population represents a unique group to study the benefits of pre-operative IMT. We propose to study 100 lung transplant patients awaiting surgery who will be randomized to receive either: 1) IMT and standard rehabilitation or 2) standard rehabilitation alone across 4 centers in Canada. Participants in group 1 will use a well-established respiratory muscle training device to train twice daily until transplantation. All participants will undergo standard rehabilitation until the time of surgery and 3-months post-transplant. In a subset of the 100 patients, muscle biopsies of the diaphragm will be performed in the Toronto program at the time of surgery. This study will determine if the research design is feasible. Secondary measures will evaluate breathlessness, quality of life, diaphragm function and cellular characteristics, and clinical outcomes 3-months post-transplant. This study will provide a unique opportunity to understand whether IMT is feasible across 4 transplant centers and get an assessment of post-operative outcomes and mechanisms underlying IMT. This study may serve as a model for examining IMT as part of pre-operative rehabilitation in a number of patient populations undergoing major surgery.