The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: Aerobic fitnessOn the speed-of-processing task, 6-min walk performance accounted for 20% of the variance in performance. The relationship was such that those who could walk further during the 6-min (and thus who had higher levels of aerobic fitness) had faster responses. Thus, aerobic fitness had a positive impact on performance of this task. Additionally, age was a significant predictor of performance. The nature of this relationship was such that older subjects had slower responses. These findings are of special interest because past research has shown that speed of processing may be one of two cognitive variables that are capable of explaining a large proportion of the age-related variance in cognitive functioning. In other words, aerobic fitness was found to be associated with the maintenance of speed of processing, which suggests the possibility that cardiovascular mechanisms may mediate the relationship between age and speed of processing and ultimately between age and performance on many cognitive tasks. read

MVV was also a significant predictor of performance on the speed-of-processing task; however, the direction of the relationship was counter to that which was hypothesized. That is, subjects who performed better on the MVV task also had slower performances on the speed-of-processing task. This variable was included to assess factors that may limit V02 and thus may have an effect on cognitive function. Because Ve is one component of V02 and patients with COPD may have a maximal Ve that equals their MVV, it was expected that a decrease in MVV would be associated with poorer performance on the speed-of-processing task. However, it is possible that MVV is not a meaningful indicator of task performance because the cognitive tasks were all performed at submaximal levels of ventilation.