The general mechanism of variation in the energy capacity of dynamic deformation with variation in loading intensity and conditions is established on the basis of experiments with various intrusive rocks. In dynamic loading, it is shown that irreversible energy absorption is observed under loads that are significantly lower than the elastic limit, and this can be associated with both viscosity and changes in the internal structure of rocks. Qualitative data on the dissipation of dynamic-loading energy in the regions of quasi-elastic and elastoplastic deformation of intrusive rocks are compared.