Which of the following is one of the two most important factors in sprint speed?

Stride length is one of the key factors that significantly influences sprint speed. When athletes sprint, the distance they can cover with each step—known as stride length—plays a vital role in determining how fast they can move. A longer stride length allows an athlete to cover more ground with each stride, therefore enhancing overall speed, provided that it is coupled with an efficient frequency of strides.

Moreover, while stride length is important, it must be optimized with proper technique and speed mechanics. Athletes who can maintain longer strides while also achieving a high frequency of turnover maximize their sprinting potential. This dynamic interplay between stride length and cadence can ultimately determine an athlete's effectiveness in sprints.

Other factors, such as leg length and body angle, may contribute to performance but do not have the same direct impact on sprinting speed as stride length does. Additionally, age is a factor that can influence performance but is not something that can be changed or optimized in the same way that stride length can be through training and conditioning.