In this study, meat from double-muscled (“culones”, mh/mh) and normal (+/+) young bulls of the breed Asturiana de los Valles (AV) as well as normal (+/+) animals from Asturiana de la Montaña (AM) was analysed during ageing at 4°C with regard to its oxidative status. Activities of the following main antioxidant enzymes were determined: Superoxide dismutase (SOD), Catalase (CAT) and Glutathione reductase (GR). In both breeds (AV and AM), lipid peroxidation (LPO) was also measured throughout the ageing period, because meat shelf life is mainly limited by lipids and proteins. All enzymes were apparently stable during meat ageing. While GR exhibited the lowest activity among antioxidant enzymes, SOD and CAT showed activity along the ageing period studied, with similar activity pattern seen in both double-muscled and normal animals, although, being advanced in the formers. In normal animals of both the AV and AM breeds, lipid peroxidation did not vary during ageing. However, double-muscled meat showed a significant increase after 7 days of maturation.