In this paper, we compare two approaches to describing the rate dependence of the strength of materials under conditions of dynamic loading with a constant strain rate. The first is based on a structural model of a brittle continuous medium with defects, which makes it possible to derive a semiempirical normalization relation to describe the rate dependence of the strength of a wide class of materials in a single normalized space. The second is based on the concept of incubation time of destruction, which is a strength parameter that characterizes the sensitivity of a material to the intensity and form of the loading impact. The interrelation and distinctive features of these two approaches are studied, as well as the rate dependences of strength for some materials are compared by modeling.