Exercise seems a simple and widely practised behaviour that activates molecular and cellular signalling cascades involved in various central nervous system processes. Despite impressive results obtained in animal studies, fitness interventions have produced less reliable effects in humans, particularly in young adults. In the present study we tested the hypothesis that an individually adapted exercise training consisting of three running sessions of 30 minutes per week for 6 weeks, has the potential to improve visuospatial and verbal memory, concentration performance, and affect in young and healthy adults. Twenty-eight students participated and underwent a graded fitness test to assess individual fitness. The experimental group took part in an aerobic running programme, whereas the control group were asked not to vary their everyday activities. We found a significant increase in visuospatial memory performance and a significant increase in positive affect on a .05 alpha level of significance. However, we observed no effects of running training on concentration performance and verbal memory. We conclude that physical activity can possibly serve as a means to improve positively valenced aspects of affect and benefit visuospatial but not verbal memory in young adults.