Clinical research. It's fairly chill in comparison to bench work (flexibility, work at home, etc.) and a lot quicker to publish in (if you have an established data source you could theoretically get most of your data very quickly and just start writing a paper). Harder to get funding for it now given the Doris Duke grants are gone. A lot of medical schools have internal funding for years off though.
Also, MPH and masters degrees can be pretty chill years off. They also provide you with a degree that can be marketable for academic positions, etc. after residency.
What exactly is the motivation for a gap year
Mostly health related and I want to take a break before things get into full swing