Even prior to admission to hospital, 5-13% of older persons of 65 years and older have low muscle mass; increasing to 50% in persons that are over 80 years old. Declining muscle mass in the lower extremities with ageing is most significant to mobility status, and the cross-sectional area of the vastus lateralis (quadriceps) muscle decreases by up to 40% between the ages of 20 and 80 years.
Older patients are most likely to come to hospital and become deconditioned; increased immobility for prolonged periods significantly reduces muscle mass and function, with 30-60% experiencing functional decline after hospitalisation, resulting in a decline in health-related quality of life and autonomy. Frailer older people (those who require a walker), those who report unsteadiness at hospital admission, and those with cognitive impairment are significantly more likely to suffer functional decline whilst in hospital. This hospitalisation-associated decline in function is associated with increased risk of readmission, nursing home placement and mortality.
Evidence demonstrates that age is not a barrier to improve aerobic fitness and strength gains through appropriate training, and the changes seen are similar to what younger people can achieve.
Kleinpell RM, Fletcher K, Jennings BM. Reducing Functional Decline in Hospitalized Elderly. In: Hughes RG, editor. Patient Safety and Quality: An Evidence-Based Handbook for Nurses. Rockville (MD): Agency for Healthcare Research and Quality (US); 2008 Apr. Chapter 11. Available from: https://www.ncbi.nlm.nih.gov/books/NBK2629/
Baumgartner, R. N., Waters, D. L., Gallagher, D., Morley, J. E. & Garry, P. J. Predictors of skeletal muscle mass in elderly men and women. Mech. Ageing Dev. (1999) doi:10.1016/S0047-6374(98)00130-4
Evans, W. J. & Lexell, J. Human Aging, Muscle Mass, and Fiber Type Composition. Journals Gerontol. Ser. A Biol. Sci. Med. Sci. (1995); doi:10.1093/gerona/50a.special_issue.11
Seals DR, Hagberg JM, Hurley BF, Ehsani AA, Holloszy JO. Endurance training in older men and women. I. Cardiovascular responses to exercise. J Appl Physiol. 1984;57:1024-1029
Frontera WR, Meredith CN, O’Reilly KP, Knuttgen HG, Evans WJ. Strength conditioning in older men: skeletal muscle hypertrophy and improved function. J Appl Physiol. 1988;64:1038-1044.