Even light exercise has benefit. Resistance training can restore muscle composition and strength at any age.
D000367:Age Factors; D000368:Aged; D016172:DNA Fingerprinting; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000235:genetics / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*