<p>Due to their lightweight, high strength, and energy absorption characteristics, porous structures are widely used, but their energy evolution during cyclic use has been rarely studied. This paper analyzes various published porous structures with different gradient strategies, through energy calculation theory and stress–strain curve integration, to obtain the total input energy, elastic energy, and dissipated energy. The results show a consistent trend, with all types of energy increasing with strain. In the initial stage, the dissipated energy is less than the elastic energy, and before the first peak strength, the input energy is converted into stored elastic energy. The quadratic function (QF) structure has the highest elastic energy, followed by the linear function (LF), graded structures, and uniform structures. A higher proportion of elastic energy at the first peak indicates a higher elastic modulus. The elastic-dissipated energy relationship allows elastic energy to be estimated from the total input energy. These findings connect the effects of gradient strategies with elastic modulus analysis, providing a new method for evaluating the mechanical performance of porous structures.</p>