MMP2 and obesity due to melanocortin 4 receptor deficiency: Souza et al. (2014) and Prestes et al. (2009) showed an increase in MMP-2 activity induced by RT (12 weeks, 3 times per week) in an obesity model and hypoestrogenism in rat skeletal muscles, which indicates that mechanical loading exercise exerts important regulatory roles in ECM homeostasis and the remodeling of muscle fibers and local connective tissue.