The benefits of sufficient activity and a balanced diet are well documented. Yet a trend emerges of spending too much time seated in front of a computer, be it at work or home. Life-logging technologies can help to keep track of, such as steps or calories. They can also give reminders and induce more physical activity, e.g., by awarding (virtual) badges. The present thesis investigates perceived barriers and benefits to the use of life-logging to understand the acceptance of these technologies.