Some Laboratory Measures of Extraversion-Introversion

The Maudsley Personality Inventory was given to a pool of 309 Ss from which three groups were selected along the extraversion dimension, two to represent each extreme (extravert N = 20, introvert N = 19), and an intermediate group ( N = 19). The three groups were equated for neuroticism. Ss were tested on the following measures: time-judgment, breath-holding, digit repetition, line reproduction, leg persistence, set change, kinaesthetic figural after-effect, and size constancy. Extraverts were superior in breath-holding, had a longer time span in digit repetition, showed longer leg persistence, greater variability in line reproduction, a tendency to underestimation in time judgment, but were inferior in arithmetic computation under slow set change conditions. No significant difference between extraverts and introverts was observed in the kinaesthetic figural after-effect or in size constancy.

Role of self-reported individual differences in preference for and tolerance of exercise intensity in fitness testing performance

Performance in fitness tests could depend on factors beyond the bioenergetic and skeletomuscular systems, such as individual differences in preference for and tolerance of different levels of exercise-induced somatosensory stimulation. Although such individual-difference variables could play a role in exercise testing and prescription, they have been understudied. The purpose of these studies was to examine the relationships of self-reported preference for and tolerance of exercise intensity with performance in fitness tests. Participants in study I were 516 men and women volunteers from a campus community, and participants in study II were 42 men recruit firefighters undergoing a 6-week training program. Both the Preference and Tolerance scores exhibited significant relationships with performance in several fitness tests and with body composition and physical activity participation. Preference and Tolerance did not change after the training program in study II, despite improvements in objective and perceived fitness, supporting their conceptualization as dispositional traits. Preference and Tolerance scores could be useful not only in ameliorating the current understanding of the determinants of physical performance, but also in personalizing exercise prescriptions and, thus, delivering exercise experiences that are more pleasant, tolerable, and sustainable.