Car analogies are a dime a dozen in computing, but they apply here as well. Not exercising is like changing the oil in your car every 10,000-15,000 miles, instead of every 3,000 - 6,000. Your car is still going to last years, but its lifespan will be shortened, and it's going to run poorly towards the end of it. The nice thing about a car is you can repair it, or buy a new one. Repairing a human is tricky, and you definitely can't buy a new one.
I'm absolutely baffled by those who put their careers or money at a higher priority than their own physical health. You really want to be rich and famous with a crappy body? Is type 2 diabetes, along with likely amputations, blindness, and erectile dysfunction, your thing? Looking forward to clogged arteries and heart disease? What about stroke, wiping away your ability to control your own body, or even being able to think or speak? Etc, etc...
I don't intend to be mean, but many American's simply don't prioritize their health high enough. People seem to have every excuse in the world not to do it, except for a good one.
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True story. My brother is enrolled for his doctoral in physical therapy. He dissected cadavers (donated human corpses) during one of his classes. My family and I went out to visit, and he was able to let us look at one.
My father, who is about 30 pounds overweight in his late-50's, hasn't really cared about his health. He eats too much high-saturated-fat ice cream, puts cream in his coffee, likes cookies with lots of butter in them, etc... I've been trying to get him to eat healthier and exercise for years to no avail.
Well, my brother was having me hold/feel the heart from the cadaver (it was already cut out of the dissected body). I was squishing some of the arteries with gloves on, and my brother said "Try squishing this Coronary Artery. Sometimes it might be crunchy from heart disease."
So I did, and WOW! It was ROCK SOLID! So much calcium and plaque had built up inside this persons heart that it completely clogged the artery. It was as if there was a pebble-sized rock inside of it.
Of course, I forced my father to put some gloves on and feel it for himself. Well, that scared the SHIT out of him! These last few weeks since, he's made a decision to stay away from high-fat foods (and has been doing so - non-fat ice cream now, skim milk in coffee, etc...). He's also putting together an exercise room.
It looks like he's in the right mindset now, which is a very good thing! Sometimes the dagger of death hanging over your head is the best motivator. :)