Inclusion Criteria:  At least 18 years old Stable medical condition Non-progressive C3-T1 AIS A-C Spinal Cord Injury (SCI) Sustained SCI at least 24 months prior to entering the study At least 15%-deficit in pulmonary function outcomes  Exclusion Criteria:  Painful musculo-skeletal dysfunction Unhealed fracture Contracture Pressure sore Urinary tract infection that might interfere with respiratory training Clinically significant depression Psychiatric disorders Ongoing drug abuse; Major cardiovascular disease Major pulmonary disease Ventilator dependence Major endocrine disorders Malignancy Marked obesity Deep vein thrombosis HIV/AIDS related illness Secondary causes of respiratory dysfunction Major gastrointestinal problems Other major medical illness contraindicated for respiratory training Pregnantcy