Lab-Based and Self-Reported Indices of Fitness Show Lowered Fitness and Insight into Fitness in Individuals at Clinical High Risk for Psychosis

Abstract

IntroductionExercise is a promising intervention for clinical high-risk for psychosis (CHR) populations, who have attenuated positive symptoms, but evidence suggests that these youth may require tailored exercise interventions. Presently, the scope of the problem is unknown, as these youth may not be reliable reporters on fitness. This issue is compounded by the fact that there have been no investigations that utilized a formal fitness assessment in this critical population. The present study aims to determine the level of fitness in CHR youth with lab-based measures, test how effectively self-report measures characterize objective fitness indices, and explore clinical factors that may be interrupting reliable self-report-an important tool if these interventions are to be taken to scale. MethodsForty CHR individuals completed an exercise survey and lab-based indices of fitness (i.e., VO2max and BMI). Forty healthy volunteers completed lab indices of fitness and a structured clinical interview ruling out the presence of psychiatric illness. ResultsCHR youth showed greater BMI and lower VO2max compared to healthy volunteers. In the CHR group, abstract self-report items (perceived fitness) did not reflect lab indices of fitness, whereas specific exercise behaviors (intensity of exercise) showed stronger correlations with laboratory-based fitness measurements. Exploratory analyses suggested that positive symptoms involving grandiosity, and negative symptoms such as avolition, correlated with discrepancy between self-perception and laboratory findings of fitness. DiscussionResults suggest that CHR individuals are less objectively fit than matched controls, and that it will be important to consider unique population characteristics when weighing self-report data.