From a Journal of Applied Physiology online abstract:
Thus, while aging led to a pro-inflammatory profile within blood and muscle, lifelong exercise partially prevented this and generally preserved the acute inflammatory response to exercise seen in young exercising men. Lifelong exercise may positively impact muscle health throughout aging by promoting anti-inflammation in skeletal muscle.
To read abstract: https://www.physiology.org/doi/abs/10.1152/japplphysiol.00495.2019?journalCode=jappl
From a New York Times article review of study:
Taken as a whole, these results suggest that long-term exercise may help aging muscles remain healthy in part by readying them to dissipate inflammation, Dr. Trappe says. But on the flip side, sedentary living seems to set up muscles to overreact to strain and remain inflamed, potentially leading to fewer muscular gains when someone does exercise.