I do it for fun and rec but not a major hobby. Have a g fisher 29er. Some of the guys I work with are hardcore into biking... They did white rim in Moab last Saturday in a single day. 106 miles, fuck that.... This is a kinda normal thing for them. They regularly do street rides over 100 miles up here also and when I say regularly I mean like 4 days a week in summer..... One does 80 miles round trip just as his work commute daily.
These dudes are fucking nuts about cycling up here.
I used to be one of those people. It's crazy how fast your fitness leaves. I used to race bikes, both on the road and in the velodrome. I used to ride my road bike up to the local ski resorts in the summer. It was nothing to ride a 100 or so miles with 7-10k feet of climbing on a saturday morning...sigh. I was in such good shape. I probably couldn't do my old "easy sunday recovery ride" these days. Sigh. I quit because I got burned out on racing and training and the whole roadie scene.
I've been off my road bike for 6 months but ride around town on my cheap mtb. I'm kinda scared to get back on one of them. It's hard to dial it back when you're used to being able to crush it
I'd prefer to mtb to get away from cars but I'd need a new mtb to do any serious trail riding. My bike now can handle fire roads and moderate single track but it's 35 pounds and makes a lot of bad noises