This paper examines various kinds of sport technology from the perspective of three normative theories of competitive sport. Sport technology represents a certain type of means to realize human interests and goals in sport. Such technology ranges from body techniques, via traditional sport equipment used by athletes within competition, to performance-enhancing machines, substances, and methods used outside of the competitive setting. Any critical and systematic discussion of sport technology in competitive sport should relate to some kind of interpretation of the main constituent of these practices: athletic performance. The paper discusses three ideal-typical theories in this respect. The first possibility presented is the so-called non-theory. As the term indicates, the non-theory is no real theory of performance. Rather, it is a theory of how sport can serve as a means towards external goals such as prestige and profit. In technological terms, the non-theory is relativistic; it accepts any kind of sport technology as long as it serves as a means to reach external goals. The second theory of performance is the thin theory. The thin theory builds on a particular sport ideal: CITIUS, ALTIUS, FORTIUS. Sport is considered an arena for the testing out of the performance potential of the human body. To end up with valid and reliable tests, performance measurements have to be accurate, and the thin theory requires equal opportunity in competitions. The implication for technology is increased demand on standardization. However, the thin theory implies no regulation outside of competition. An acceptable technology is simply a performance-enhancing technology. A third, thick theory of performance does not just require equality of opportunity; its basic premise is that sport should be an arena for moral values and for human self-development and flourishing. Technology that requires athletic efforts and skills, to which there is equal access, and that does not represent unnecessary risk for harm, is considered not merely as acceptable but as constitutive to the value in sport. Expert-administrated technology that enhances performance without athletic effort or which exposes athletes to the risk of harm is problematic and should be avoided. In a final, critical comparison, it is argued that the thick theory represents the only possibility towards a sound ethics of technology in sport.