Light, Exercise Intensity and Mood in Overweight

Inclusion Criteria: * Body Mass Index 25 - 35 kg/m2 Exclusion Criteria: * Women who are pregnant or breast feeding, * Other clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, etc.), * Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant * Previous enrolment into the current study * Participation in other studies in the last four weeks * Systolic blood pressure \> 170 mmHg, diastolic blood pressure \> 100 mmHg * Shift work in the last two months * Travels across time zones in the last four weeks * Use of photosensitisation drugs * Clinical manifest depression * Cardiovascular diseases which reduce age-appropriate exercise capacity