When I was recovering from being in a PhD program (I was experiencing pretty extreme isolation), my wife and I re-started aikido. Dojo has been a great benefit to our lives. We get:
- a friendly community of close-knit people who ask about your welfare if you’re absent
- vigorous aerobic exercise
- A well-lit space during the dark winter months
In a lot of ways, it’s a bit like a church, but without the religion, and a whole lot more exercise.
Also, this isn’t unique to aikido. I’ve also done judo and another style of jujitsu and found similar experiences (albeit with a little more difficulty finding a non-testosterone-soaked environment). Presumably other styles offer this too.