Phenotyping and the characterization of chronic obstructive pulmonary disease (COPD) is currently an active area of interest. The perspectives gleaned from evaluating COPD in the context of exercise lend new insights into this endeavor. Pulmonary rehabilitation centers are uniquely positioned to generate such clinical observations and have enhanced an understanding of the disease processes that are involved in COPD. This review and commentary discusses the various patterns of exercise intolerance and characterizes COPD from the perspectives of clinicians caring for persons with COPD.