Rate of Perceived Exertion and Cardiorespiratory Fitness in Older Adults with and without AD

Abstract

Exercise has many benefits for physical and cognitive health. However engagement in and adherence to exercise is challenging. There are many barriers to exercise in older adults including subjective exercise difficulty, or rate of perceived exertion (RPE) independent of objective cardiorespiratory fitness, measured by peak oxygen and carbon dioxide exchange (VO2 peak). Subjective perception of exercise difficulty may especially be a barrier to exercise in individuals with Alzheimer’s disease (AD). RPE is the most commonly used measure in exercise research, yet the relationship between RPE and objective fitness is not fully understood in older adults with and without AD. This relationship is important in understanding how to best support initiation, engagement, and maintenance of exercise in this population and is a first step in understanding appropriateness for use in this population. Multilevel modeling (MLM) statistical analyses were performed to explore the relationship between objective and subjective measures of fitness in older adults with and without AD during a multi-stage graded exercise test. Results indicate a negative relationship between objective fitness and subjective effort. Independent of cardiorespiratory fitness, older age, female gender, cognitive impairment, and use of heart medications each predicted greater self-reported effort (RPE) during exercise. Results are discussed in terms of social psychology phenomena and potential neuropsychological deficits leading to increased subjective feelings of effort. These findings establish the relationship between actual fitness level and perceived effort, highlight ways to support exercise behavior, and direct future exploration of barriers to exercise among older adults with and without AD.