It is "meditational" for me as well. Running is my favorite place to think and to relax, but I think this is more due to independence and solitude.

If I want to spend an hour running six miles, nobody would deny me that.

I've done some tris, but mainly prefer to just do the elements, usually 1-2 at a time. But I also surf, which takes time and money (at least enough to live near the coast) and that's not ergically expensive. But there is a "blue sky" effect. Some of the biggest, most important thoughts I've had are alone in the cold dawn waters waiting for a wave. Others have been while chatting with a trusted confidante on the bike or the trail (no one talks while swimming, that I know of...).

If you look at the research, aerobic exercise seems to have positive effects on cognition, while lifting weights has almost none.

Bouldering has that effect on me. Give it a try if there is a gym close to you