The creation and adaptation of scales or inventories assessing specific circadian typologies has been a predominant focus within the field of chronopsychology. The present study addressed the psychometric properties of two scales of morningness-eveningness: the Morningness Composite Scale (CS; Smith, Reilly, & Midkiff, 1989) and the Early/Late Preferences Scale (PS; Smith, Folkard, Schmieder, Parra, Spelten, & Almirall, 1993). Internal consistency and factor invariance of the CS and PS were analyzed in two samples: a group of 203 university students (age range = 19-30) and a group of 125 working adults (age range = 31-65). Results indicated satisfactory internal consistency for both full scales with each age group and confirmed the factor invariance across age for the two CS factors and one of the PS factors. A higher tendency in morningness on both scales was noted in the adult sample.

Few studies analyze determinants and patterns of physical activity among college students, so it has not been possible to carry out effective interventions to promote this practice. The aim of this study was to analyze the associations between some personal, social, and environmental determinants, practice of physical activity and future intention to practice in a sample of 639 university students (321 men and 318 women), mean age 21.43 years (± 2.78). Physical fitness self-perception, physical activity history, and coach's support to practice physical activity have a direct effect on the practice of physical activity and an indirect effect on future intention to practice, both in men and women. The practice of physical activity has also a direct effect on future intention to practice. Likewise, the participation in sport competitions predicts practice of physical activity and future intention in men, whereas being a member of a sports club predicts practice and future intention in women.

Addiction to and problematic use of the Internet are relatively recent phenomena whose scope, characteristics and correlates have begun to receive increasing attention by clinicians and researchers alike. The purpose of this study was to examine the relationship between time spent connected to the Internet and the variables that indicate a pathological and addictive use of this technological resource. The sample was comprised of 1,301 university students of both sexes (927 women and 374 men), with ages ranging from 18 to 30 years old. The results showed that, although most people use the Internet appropriately, users who invest higher quantities of time in the Internet more frequently exhibit connection behavior that is controlled through negative reinforcement, a high degree of arousal when online, loss of control over connection behavior, changes in health-related habits, and interference in the social, family, academic, or work spheres. These findings suggest that excessive Internet use is associated with the onset of several problems that are similar to those associated with other behavioral and technological addictions.