Running speed is critical for sport performance and is the basis for sport selection. The 100 m sprint is the ultimate expression of running speed. As the 100 m sprint is the product of one-dimensional power, sport performance requires one-dimensional power and the translation of that power into change-of-direction power for performance. These would appear to be very different skills, yet the training techniques are largely similar. The purpose of this paper is to review the characteristics of 100 m sprint performance as related to running speed for sport performance and to explore the mechanical and physiological structure-function relationships that support these performance characteristics. Both sprinting and sport performance require great acceleration which depends heavily on muscular strength and power. Undoubtedly, muscle fiber type plays a critical role in determining running speed. However, muscle architecture, specifically muscle fascicle length and localized muscle distribution (muscle shape), appear to confer even greater performance specificity. Both sprinting and sport performance rely heavily on muscle-tendon stiffness for the efficient application of force for what is ultimately change-of-direction power, but with a different point of emphasis and outcome. While the energetic requirement for competition is significantly different,sprinters and sports performers have similar anaerobic and aerobic capacities suggesting an equivalent metabolic conditioning. Given the dependence of running speed on muscle force/power and similar training adaptations, resistance exercise training appears to be a specific analogue for sprint performance and is critical for improving running speed. Ultimately, it appears that the mechanical and physiological structure-function relationships are quite similar only applied in a different manner for speed and purpose. Gender and race differences in structurefunction relationships result in some changes in emphasis for performance and for training.