With the emerging of digital tools that track personal data, more humans start to explore these tools for self-discovery and self-exploration. There are still lack of proper instructions, to the public, how to use these tools to aid and efficiently benefit people. The aim of this research was to find out why individuals use digital tools to collect data about their bodies, and how they use this data to expand their knowledge about their body and mind. The research was based on a semi-structured interview where 10 participants was interviewed about their daily use of self-tracking data with the help of digital tools. During the research we found four different themes of how the participants were using their data generated by their activity trackers. By understanding activities that goes on inside of them, the participants have been able to adapt different techniques to optimize their training and expand the understanding of their body and mind. The study shows there are many different reasons why tracking yourself is a wildly considered option; motivation, measurability, self-awareness, willingness to improve and prosperity, are among these reasons. Our findings show that a lot of people don’t reflect on their own usage, and further shows how different attitudes towards tracking yourself differentiates between a positive or negative outcome. It then boils down to the importance of reflecting on how and why you are using self-tracking, if used in the correct way, self-understanding via digital tools can help individuals to become more self-conscious and enjoy the journey to a more active life.