Effects of aerobic fitness on cognitive performance as a function of dual-task demands in older adults.

The objective of this study was to examine the effects of aerobic fitness on cognitive performance under varying dual-task demands in older adults. Thirty-four participants (mean ± SD age: 68.6 ± 10.1 years, 24 females) were included in this study. VO max was assessed with the Rockport 1-mile walk test (range = 6.68-45.57). Participants engaged in a cognitive task, the Modified Stroop Color Word Test (MSCWT) on a self-paced treadmill while simultaneously standing or walking. Performance on the Stroop Test was measured as interference of the accuracy score. Participants demonstrated over a 4-fold increase in SI when going from Incongruent to Switching MSCWT blocks across both standing and walking tasks. Furthermore, there was a significant interaction between the MSCWT block and VO max in Stroop interference, such that Switching Stroop interference demonstrated greater changes due to VO max, in comparison to Incongruent SI, even after controlling for age, gender, body mass index, and years of education as covariates in analyses. These results provide evidence of a relationship between aerobic fitness and cognition, suggesting that dual-task interference may provide a sensitive indicator of effects of an aerobic intervention program on the cognitive performance among older adults.