Bipolar as well and this was my first thought. I am not always active, but I was in my teenage years because I couldn't deal with my bipolar and BPD mother and NPD father. Getting out and doing stuff was the only way to stay safe and keep myself from doing something destructive.

I watch a lot of videos on mountain climbing, scuba diving, etc, and I have said time and time again that so much of that, "call of the wild," is mania. Lots of broken relationships and a drive to do something they know could kill them because it's the only time they feel real peace. That isn't something I would expect of mentally healthy people. It doesn't seem healthy when people throw their life savings and families away to do some of these things. Not that they can't ever be healthy, they absolutely can. Just that none of what I have learned makes me think this study was looking in the right places.