I had fantastic health (speed and endurance) (and few illnesses or injuries) all my life. I never had to work at it. Never went to doctors much either.
The last couple years I had a couple health scares. They thought I had prostate cancer (killed my dad), and then a spot on my lung was maybe lung cancer (smoked the evil tobacco 40 years). A bunch of doctors, MRI, CT scans later, I had none of that.
My mom at 93 has a very good handle on old age health, so I listened to her, changed my diet significantly (but not radically) and began exercise (walk 2-3 miles daily, and get outside for work every day possible), and quit cigarettes (hardest thing I ever did, though I have backslid to some cigars). Weight loss was never my goal, but I lost 20-25lbs, gradually (suddenly all my pants and belts were too big). So I feel better, sleep better, have more energy, and am more alert than for many years.
Besides, being a couch potato is boring.
I have been at my house and property all during this time, and now have fixed, repaired, replaced, cleaned everything up so much, I now have to work at finding things to do. So yesterday, I pulled out a pile of scrap lumber (only needed 2 new 2X4s) and my circular saw, tape measure, lithium drills, builders square, and belt sander, and built a big bench. I am only a hack carpenter, but I now have a 6'8" long, 20" high, 16" wide bench with one coat of cedar stain. 2d coat today. It will sit out in my backyard driveway along the fence and serve as an outdoors work bench. It's not a thing of beauty, but it's rock solid. The T-111 seat makes it light enough for me to move around.
Already did my 3 miles this morning.

Every man should do what he wants, but old age will screw you up (eventually), and my program is a good one to follow.
I've used that saying for years now. Didn't know about the song.
Jess, some people I know think I'm extreme with my lifestyle.. They may be right. I tell people they don't have to be like me to stay healthy, strong and fit. A simple template like the one you have is a very good one.
The key is to keep the body moving constantly while feeding it food that will rot. Any food that doesn't rot is not food. Fasting also is extremely valuable, it gives your body a chance to do needed repairs well not being burdened with digestive action.
If people get out and walk daily, pick up something heavy-ish and put it over their heads daily, carry something heavy daily, move all of their joints every day, practice balancing on one foot, practice getting up and down off of the floor without using hands, practice something like Tai Chi or dancing or whatever movement patterns you like, work on holding a better posture while standing and walking.. The list goes on and on.
The whole point is to just be consistent, there is no wrong way.. So long as you just keep doing it everyday.