I started a Meetup group a few years ago as a hobby despite no formal training. My group has now outlived many others and I'm surprised by how many people I meet on hikes who have heard of my group and actually listen to my advice these days.

Don't forget about the guy either who ran an ultra marathon with no real training here in Australia and ended up winning . Turned out his goofy style of running was actually more efficient than normal jogging.

I know someone who is the world record holder for highest gym class She absolutely deserved it. She's not nims, but she gave it a shot

I know a lady with Parkinson's who is a cross fit champ. People like you would tell her she should give up

As long as you're safe and not a danger to others, definitely give things a shot.