Nothing earthshaking here but we did show that; "Despite its clinical utility, #6MWD and 6MWD decline do not correlate strongly with spirometric or radiographic markers of disease severity or their decline. We believe this is likely due to the nature of the test: 6MWD is self-paced and typically does not elicit physiologic exercise limitations. Correlates of 5-year decline in 6-min walk distance in the #COPDGene cohort" People tend to think that measuring the distance a person can walk in six minutes is an exercise test when it's really measuring functional exercise performance rather than physiological capacity. https://thorax.bmj.com/content/thoraxjnl/early/2026/04/13/thorax-2025-224183.full.pdf?ijkey=Eyz4AtLxZ5KIWQD&keytype=ref #Science #Epidemiology