Saving Time for Patients with Moderate to Severe COPD: Endurance Test Speed Set Using Usual and Fast Walk Speeds - See more at: http://journal.copdfoundation.org/jcopdf/id/1031/Saving-Time-for-Patients-with-Moderate-to-Severe-COPD-Endurance-Test-Speed-Set-Using-Usual-and-Fast-Walk-Speeds#sthash.jBiR0RTG.dpuf