Reliability of Peak Treadmill Exercise Tests in Mild Alzheimer Disease

ABSTRACT

Introduction: The purpose of this study was to determine the reliability of treadmill peak exercise testing in people with very mild-to-mild Alzheimer disease (AD). Methods: Sixteen subjects with very mild-to-mild AD performed graded peak treadmill exercise tests twice within a 14-day period. Heart rate, oxygen consumption, and respiratory exchange ratio (RER) were continuously monitored. Peak values were analyzed for absolute level of agreement. Results: Fourteen participants (87.5%) completed testing. Reliability was excellent with total peak oxygen consumption (VO_2peak) (ml/kg/min) highly correlated across the two tests (r = 0.94, p < .001) with an intraclass correlation coefficient (ICC[3,1]) of 0.92 (95% confidence interval (CI) = 0.78, 0.97). The standard error of measurement (SEM) for VO_2peak was 1.29 (95% CI = 0.88, 1.89). Conclusions: These results indicate that peak exercise testing on a treadmill is reliable in the early stages of AD.

KEYWORDS::

• Alzheimer's disease
• cardiorespiratory fitness
• dementia
• fitness
• VO₂