Inactivity due to a sedentary lifestyle or a stay in hospital has a more severe impact on muscles with age, according to an Italian study published in the Journal of Physiology.
Researchers found that the same period of inactivity has a greater impact on the muscle power of the lower limbs of the elderly than young people. Muscle strength in the lower limbs is essential for movements like climbing the stairs.
The research, conducted by the University of Udine in conjunction with the University of Padova, involved studying the impact of complete inactivity in a group of older people (aged 55-65 years) who were bedridden in a hospital environment for two weeks. Their results were compared with younger subjects (aged 18-30 years).
Reporting on the findings, the Physiological Society said that in the older subjects, there was a difference in single muscle fibre response to disuse, a more pronounced loss of muscle mass and a change in how muscle contraction is controlled by the nervous system compared to the younger individuals. The recovery phase was also more difficult in the older group.
Lead investigator Carlo Reggiani commented: “While clinical and epidemiological data on inactivity in the elderly are abundant, experiments on disuse and inactivity are seldom performed in elderly for several reasons. The results obtained are relevant not only to understand the inactivity-dependent enhancement of the decline (in muscle mass, metabolic health and functional capacity) but also to design new rehabilitation protocols where timing and intensity of the sessions are optimised.”