What is Sarcopenia?
Sarcopenia refers to the gradual decline in muscle mass and increase in adipose storage as a result of aging . Not to be confused with atrophy, the degradation of muscle due to inactivity, rather as a result of muscle wastage. It is linked with:
- functional disability
- decreased bone density
- glucose intolerance
- decreased hot and cold tolerance 
There are various molecular mediators that are effected by these age related changes including fiber size and strength, mitochondrial homeostasis and apoptosis. Factors that further effect sarcopenia are:
- physical inactivity
- oxidative stress
- abnormalities in growth and sex hormones 
Between the ages of 50-70 years there is an approximate 30% reduction in muscle strength as a result of sarcopenia. 
Resistance Exercise in Reducing Sarcopenia
Evidence has shown that resistance training is the best way to slow or reverse sarcopenia. Resistance training enhances strength, power and mobility function and induces skeletal muscle hypertrophy. In the elderly resistance training also induces the muscle expression of IGF-I, myogenic regulator factors and IL-6 to contribute to muscular hypertrophy by regulating function of satellite cells, which in turn will assist in preventing the onset of sarcopenia. Even just one session of resistance exercise for elders can enhance the synthesis rate of muscle protein.  Resistance training also enhances the nervous system leading to an improved functional capacity during everyday tasks. This is because the loss of muscle mass with aging may be the result of impaired capacity for axonal reinnervation of deinnervated muscle fibers, which would attribute to the enhancement of the nervous system through resistance training.
Although the following guidelines are best for reducing the effects of sarcopenia, a participant who is involved in any form of resistance training is better then one who doesn't train at all.
- Complete 8-10 exercises involving all the major muscle groups. Multi-joint exercises are recommended.
- Have the participant perform 10-15 repitions of each exercises
- 1 set of each exercise is sufficient for elderly clients
- The intensity of exercise should be 'somewhat hard', roughly 12 or 13 on the Borg's scale
- Resistance training should be performed at least twice a week, with 48 hours between each session 
In addition, adequate protein and energy intake are key for further management of sarcopenia. 
When determining the amount and frequency of a strength program, attention to overloading the patient needs to be considered as intensive regimes will decrease the effective gain in muscle strength and mass in the elderly. Ensure the program is individualized to the participants needs and current health status.
Correct technique must be maintained at all times, as the injury risk in the elderly is much greater. Have caution with eccentric training as this creates greater muscle soreness in the elderly. Free weights are excellent tool to use as they not only increase strength but also balance and coordination. 
- Kamel, H. K. (2003). Sarcopenia and Aging. Nutrition Reviews, 61(5 pt 1), 157-67.
- Vella, C., & Kravitz, L. (n.d.). Sarcopenia: The Mystery of Muscle Loss. Exercise Science at UNM. Retrieved October 24, 2011, from http://www.unm.edu/~lkravitz/Article%20folder/sarcopenia.html.
- Campbell, W. W. (2007). Synergistic Use of Higher Protein Diets or Nutritional Supplements With RT to Counter Sarcopenia. Nutrition Reviews, 65(9), 416-22.
- Sakuma, K., & Yamaguchi, A. (2010). Molecular Mechanisms in aging and current strategies to counteract sarcopenia. Current Aging Science, 3(2), 90-101.
- Aagaard, P., Suetta, C., Caserotti, P., Magnusson, S. P., & Kjaer, M. (2010). Role of the nervous system in sarcopenia and muscle atrophy with aging: strength training as a countermeasure.. Scandinavian Journal Of Medicine & Science In Sports, 20(1), 49-64.
- Rolland, Y., Dupuy, C., Abellan van Kan, G., Gillette, S., & Vellas, B. (2011). Treatment Strategies for sarcopenia and frailty. The Medical Clinics of North American, 95(3), 427-38.