1Middle age — the life stage between young adulthood and old age, roughly the 40s to 60s, often associated with an established career and family.
彼は中年になってから健康に気を使うようになった。
He started paying attention to his health after reaching middle age.
中年になると、体力の衰えを感じることが増える。
Once you reach middle age, you start noticing your physical strength declining more often.
中年の男性が公園でジョギングをしていた。
A middle-aged man was jogging in the park.
中年になって転職を考える人も少なくない。
Quite a few people consider changing careers once they reach middle age.