I'm an 82-year-old man, and in the last couple of years I seem to have lost all the muscle in my thighs and upper arms.  I walk a lot for my part-time job and at home.  None of this seems to help.  Is this just the result of getting older?
D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D009133:Muscular Atrophy / Q000209:etiology / Q000534:rehabilitation*; D016474:Weight-Bearing / Q000502:physiology*