The ageing of biological tissues can be accelerated by many factors, mainly of physiological and nutritional nature. In the case of skeletal muscle tissue, one of the main consequences of ageing is a progressive loss of muscle mass and a worsening of the quality of muscle tissue, termed "sarcopenia". The correlation between the deterioration of muscle tissue and what we usually refer to as the "lifestyle", although being the subject of several studies, up to now has been considered only from a clinical and a statistical viewpoint. However, the construction of a sound mathematical model of the muscle tissue, accounting for the changes due to ageing, can provide a more refined quantitative tool. Such a tool could determine in an improved way the variations of some measurable physiological parameters, such as the mass and the electrical impedance of the tissue, caused by the variation of other controllable factors, such as diet, physical activity, pharmacological treatments, air pollution exposure. A specific mathematical model, once implemented on a computer, makes it possible to perform "virtual" experiments, facilitating the search for a suitable treatment of sarcopenia. Moreover, test situations can be studied which would not be reproducible in vivo, such as drug overdoses, extreme nutritional deficiencies, environmental overexposure to harmful substances, and so on.