in harness
US /ɪn ˈhɑːrnɪs/
UK /ɪn ˈhɑːrnɪs/

1.
仕事に復帰して, 現役で, 職務に就いて
working or performing one's duties, especially after a period of rest or inactivity
:
•
After a long vacation, it's good to be back in harness.
長い休暇の後、また仕事に復帰できて嬉しい。
•
The old politician was still in harness, actively participating in debates.
その老政治家はまだ現役で、活発に討論に参加していた。