The objective of this study was to evaluate the impact of an anabolic implant and its use with the beta-adrenergic agonist zilpaterol hydrochloride (ZH) the calpain proteolytic system activity across specific areas of the beef strip steak over two aging days. Crossbred heifers were blocked by weight and randomly assigned to one of three treatments: 1) no implant or ZH (CON), 2) implant, no ZH (IMP), and 3) implant and ZH (IMP+ZH). At slaughter, strip steaks were collected and aged for 3 and 14 d. Samples were evaluated for Minolta objective color scores, pH, bioelectrical impedance analysis, and were then cut into lateral, lateral/medial, and medial sections. Protein was extracted from each section, and the calpain proteolytic system was evaluated. A day of aging effect was seen in protein degradation, along with a treatment by section interaction proteolytic activity. No differences were found in pH or color by treatment.