I work in software, and I've seen far too many guys in my industry who are either skinny as a rail and surviving on Cheetos dust, or painfully overweight. Had several co-workers croak unexpectedly, at shockingly young ages.
It's a real problem in the industry. People simply plop themselves down at their computers and forget to do anything else for an entire day.
I have kids, and refuse to let them lose their dad early, so I hit the gym for an hour in the mornings, at least every other day. I do a mix of cardio and weight training. I also never stay seated for longer than 45 minutes.
Seriously, guys... If you work in the software industry, make a habit of getting up and moving around. It doesn't actually take much to reap enormous benefits just from staying more active.
Five-a-side football (soccer). I'm not a sporty person, but started going with a local group a few years ago and have reaped the benefits of doing some intensive team exercise once per week. I go with a bunch of guys way older than I am, and it's amazing how fit and healthy they are compared to the average person I meet of their age. I certainly plan to keep this up so long an injury doesn't prevent me.
Breathing, even though breathing is extremely dangerous. Evidence shows that 100% of all people who breathe will die. This can be traced back genetically; everyone who breathes was born to people who had also breathed during their lifetimes.
What I'd like to do? Play Pente with friends and family in the morning in a cafe. It's an easy going game that you can have conversations over and it is a family favorite of mine.
Realistically? Forage for mushrooms and be successful at hunting in a post apocalyptic nuclear wasteland.