This paper from Aging Research Reviews discusses current scientific thought on the connection between accumulated damage to mitochondrial DNA and sarcopenia, the progressive loss of muscle mass and function with age: " Many key theories on aging describing the mechanisms underlying sarcopenia are now focused on the mitochondria because of their dichotomous role in controlling life and death processes within myocytes. ... Evidence supports that apoptosis occurring in aging skeletal muscle may be due, in part, to the progressive decline in mitochondrial function and the resulting energy depletion within the cell." Damaged mitochondria seem to play an important role in many of the conditions and failure modes relating to age-related degeneration - methods to repair or prevent this damage will be most welcome.

Link: http://dx.doi.org/10.1016/j.arr.2006.03.002