My primary exercise is hillwalking. I try to get in at least 10,000 steps a day. 20,000 would be an optimum target.
While I am walking I do a lot of "slow thinking." I arrive at viewpoints and conclusions that I cannot reach any other way, certainly not while glued to the screen. I also listen to podcasts while walking. Amazing what you can learn from an hour a day of podcasts. I find it hard to take an hour out to read each day, but somehow podcasts make that possible, I guess justified as multitasking.
I also go out on the bicycle as often as possible and do a 30 km or so ride.
Another sort of slow thinking state of mind, or at least a totally different state of mind, is working with my hands in the workshop. A different part of my brain kicks in, the saw blade starts rotating. This is refreshing in a way nothing else is.
Workouts I do in the office using the iPhone "You Are Your Own Gym" app, which is a bodyweight training program. I monitor this on the buddy system with a friend via text messages. I often miss these sessions, I need to do more.
When the weather is good and the wind is really intense I go sailing. I have a laser dinghy at the local marina. This gets one into another slow thinking mental state like walking, only different. Highly recommended.
I recently discovered that here on the lake we have some insanely intense windsurfing, further up the lake, so one of my goals for next year is going to be to learn windsurfing and join the windsurfing community on the lake. Keep learning something new.