The objective was to examine daily health-related habits and physical activity during free time in a group of young people, with the aim of analysing what types of habits are developed and the associations existing between these habits. A cross-sectional and observational study was carried out. The sample was composed of 1132 young people from Castilla-La Mancha (Spain), 53.4% women and 46.6% men, between 17 and 25 years old (M = 20.63; DT = 2.01). The instrument used in this study was the questionnaire of assessment of health-related habits (QAHH). Different ranges of age and gender were taken into account in the analyses. The results showed low rates of physical activity, with only 25% of the participants practicing physical activity in their free time. Regarding gender, no differences were observed between boys and girls in terms of the level of physical activity practice. The inferential analyses revealed several significant relationships between the habits of leisure time and the practice of physical activity. The analyses also revealed that alcohol consumption, tobacco consumption and Internet were used as means to escape from everyday life. The most frequent free-time activities of the participants during the week were the use of new technologies and the consumption of harmful substances. During the weekends the most frequent ones were physical activity and consumption of harmful substances. While the relationship between physical activity, health-related habits and leisure time in young people is complex, these results indicate that physical activity should be promoted in young people, especially during the week and as a healthy alternative to the consumption of harmful substances. To do this, professionals of different fields (education, psychology, sports sciences, nutrition and medicine, among others) should work together.