Animal models, mainly murine, stay as a fundamental resource in diverse research pursuits, notably contributing to significant strides in discovering novel treatments for therapeutic applications. Preclinical assays must consider the existence of self-recovery mechanisms in the murine species to achieve a well-designed control group. This study focuses on unveiling the innate rapid regenerative capacity of rat liver by utilizing the thioacetamide-induced sub-chronic liver injury model. Employing histopathological, biochemical, and molecular liver function tests, we assessed the recovery of liver tissue functionality. Moreover, animals were housed with voluntary running wheels and locomotory activity was recorded and employed as an indirect index of overall animal recuperation. Remarkably, basal locomotory activity reestablished to normal levels only two weeks post-thioacetamide exposure. Our results raise vital considerations about the importance of temporal synchronicity in comparative assays to validate the real action of treatments, emphasizing the role of the rapid rat liver endogenous self-recovery.