How do you build a habit of exercising when you genuinely hate it?
Stop trying to enjoy the activity and focus on making it easy to start and hard to skip. Attach it to something existing — right after dropping the kids, immediately after work clothes come off — so it inherits a slot rather than competing for one. Pick the least unpleasant option available rather than the most effective one, since something done beats something optimal skipped. Many people who hate the gym are fine with cycling, swimming or badminton. And separate the activity from how you feel about your body, which is often the actual source of the aversion.
Answers
Badminton got me active after a decade of failing to like the gym. Nobody says sport counts and it does.
The last line is the real one. For years the aversion was not to exercise, it was to how I felt doing it.