Cyclic-deformation behavior of low-carbon steel and copper under constant-stress amplitude and in a two-step stress change has been studied in the intermediate life range. Under constant-stress amplitude, there is initial softening followed by a hardening process in low-carbon steel. In the case of copper, hardening sets in from the initial stages of stress application. The total hysteresis energy absorbed is not a material constant, but depends on the applied stress. The strain-hardening/strain-softening behavior under the second stress level is different from the standard fatigue tests and is dependent on the first stress level. An energy-based analysis has been found to predict fairly well the cumulative damage life in low-cycle fatigue.