Within the scope of the linear viscoelasticity theory, the change in the inner energy of a viscoelastic body is induced either by heat exchange or by a work performance. The first law of thermodynamics, balance equation of a closed system is mostly referred when the thermodynamic consistency of some rheological model is required. Accordingly, within the frame of the isothermal viscoelastic investigation we just distinguish between the stored and dissipated energy. And this is the issue that the paper is focused on. Subjected to a load, the one degree of freedom viscoelastic models’ behaviour is traced, together with the observation of the energy – total, stored and dissipated. Nevertheless, the only stored energy in viscoelastic model is potential energy. General considerations are applied on Maxwell model subjected to the standard both creep and relaxation tests
