I noticed, I really don't get much Zen going when I'm biking. My mind is always all over the place. Occasionally I will tell my mind to focus in and pay attention only to what is around us. But it never lasts long.
One of the coolest things that happens biking is when you get to smell woodsmoke. Millions of years of association of company, food, women flood your brain. Totally hard-wired, nice!
I've always felt like getting a massage I should be able to turn my brain off and just let it dwell in the sensation, but Zen not so much there either. Probably because it's too easy to get some napping in.
Playing music doesn't wind up being Zen either. Say for instance, I am just about done working up "Shaky Ground". One of the drummers at the jam told me that was one of his favorites, so I thought I'd work it up for him. I wind up playing the same lick over and over for the whole song, except for 3 bars on the 4 and 1 on the 5 for the solo. So for something like that, I practice the lick over and over until it is committed to muscle memory, and then start working on singing the lead over it. Interesting, I thought I was ready to do it tomorrow, but tried it tonight and the 2 brains required, 1 for the guitar lick and 1 for the vocals, refused to disengage for the 1st 4 measures of the vocals. So, need to practice a few times more, give the muscle memory a few more reps.
But the point is, it winds up being not very Zen. The only time I think I get Zen playing music is when I'm really clicking on a lead. But, at our jam, I really focus on playing rhythm guitar, singing, and leading the band, which involve enough components that it doesn't lend itself to getting into a Zen groove, and which often lead me to skip taking a lead.
I guess not surprisingly, the most Zen place I currently wind up going is when I get In The Zone writing code. I've been doing it as a full-time job for 40 years. When you get In The Zone, the beautiful, interconnected, white towers of logic out of which you build software become the whole of your existence. You are the logic and the logic is you.
So I guess that's why I still like coding. Getting In The Zone coding is by far my greatest current source of Zen.