Objective. To determine the association between perceived exertion (RPE) and physiological variables and to determine thepredictive factors of RPE during submaximal and maximal exertion in older adults. Method. Older adults from Kansas (n = 100)and Costa Rica (n = 79) performed a submaximal and maximal stress test. RPE, education level and a total score of cognitivefunction (CFTS) were collected. Correlation and multiple regression analyses were computed using RPE as the criterion variableand oxygen consumption (VO2), respiratory exchange ratio (RER), CFTS and education level as predictors. Results. ere was asignicant correlation between VEP and RER (r = 0.22, p = 0.029) at maximal exertion. e RPE predictors for women wereVO2, RER, and CFTS at different stages of the test. For men, VEP was predicted by RER, education level, and VO2 at differentstages. Conclusion. Metabolic and physiological variables predicted RPE in older adults. Age, cognition, and heart rate wereunrelated to RPE at maximal exertion, and RER predicted RPE scores during submaximal and maximal exertion.