Muscle Wasting and Ageing
As we age, it is important to maintain your levels of exercise and a healthy diet. Research shows that aging is associated with a reduction in skeletal muscle mass, a condition known as sarcopenia (Churchward-Venne, Breen and Phillips, 2013). Sarcopenia results from decreased levels of strength training combined with a reduced sensitivity of the aging muscles to absorb protein (Churchward-Venne, Breen and Phillips, 2013). As a result, increased sacropenia leads to decrease in muscle strength, reduced capacity to perform activities of daily living and a greater risk of falls and fractures.
Lack of exercise has been shown to be the primary factor in sarcopenia, with just as little as 14 days of reduced or no exercise sufficient to cause a decreased uptake of protein and loss of muscle. Interestingly women typically have less skeletal muscle than males, however women see less muscle lost as a result of age compared to men. The time course is not yet clear, but muscle lost in the elderly due to inactivity is difficult to restore, even with an aggressive resistance training program.
As we age, a regular exercise program will enable us to live an active lifestyle, maintain cardiorespritory fitness, strength and muscle size, as well as increasing the longevity of life (compared to someone who doesn’t exercise). Additionally, the maintenance of physical exercise is fundamental for skeletal muscle protein absorption. The protein required within our diet has been suggested to be around 35-40 g of protein (in meals, especially after exercise) to be most effective for stimulation of the muscle protein synthesis in elderly people. (Churchward-Venne, Breen and Phillips, 2013)
Srikanthan and Karlamangla (2014) state that muscle mass is associated inversely with mortality risk in older adults independent of fat mass and cardiovascular and metabolic risk factors. In addition, traditional cardiovascular risk factors like atherosclerosis (leading to reduced blood flow) are reduced with regular exercise. Resistance (strength) training is seen as the most recognised modality of exercise to promote lean tissue. Low load (light reps) and high volume (more sets/reps) stimulated a greater response for elderly than higher load resistance exercises. (Churchward-Venne, Breen and Phillips (2013).
To prevent the loss of muscle and to maintain your activities of daily living you will need to keep on top of your training and nutrition. Age is not an excuse, and changes in body composition rather than focusing on fat loss, should be considered to create change and increase longevity.
Churchward-Venne, T. Breen, L. Phillips, S. (2013) Alterations in human muscle protein metabolism with aging: Protein and exercise as countermeasures to offset sarcopenia. International Union of Biochemistry and Molecular Biology. 40(2) 199-205
Srikanthan, P. Karlamangla, A. (2014) Muscle Mass Index as a Predictor of Longevity in Older Adults. The American Journal of Medicine 127, 547-553
BAPPSC(EX. & SP.SC)
accredited exercise physiologist