This document summarizes research on the effects of self-talk in fitness. It discusses that self-talk, whether positive or negative, can impact people's ability to exercise and achieve fitness goals. The document reviews several studies that show positive self-talk is beneficial and can improve performance, whereas negative self-talk generally hinders performance. However, some research has found negative self-talk can be motivating for some individuals. The key is becoming aware of one's self-talk and replacing negative thoughts with positive self-talk. Developing a self-talk plan and using techniques like keeping a logbook can help people gain control over their thoughts and improve their fitness through changed self-talk.