Another +1 for health, which is easy to improve by exercising. I started exercising (simple pushups and pullups) in 2019 and running a year ago. My social life has improved by this as well, it's just easier to do things when you're healthy. People also start making remarks about my physique, which is also nice :)

I was lucky to make new intimate friends as well around that time, which also really helps feeling connected. Exercise you just do, but for friendship you need some luck.