I’ve long thought about how one’s performance, both mental and physical, changes with age.
The common narrative is that it simply deteriorates, but I think that’s a bit simplistic. We all know, or at least know of, people in their 60s who run mental and physical circles around people in their 20s.
A simple map
I think I’ve cracked the code of how this works.
Basically, what you’re capable of doing at the top end of mental and physical fitness doesn’t change that much as you age, but the punishment for not being in that top shape gets more and more severe as you do.
So, let’s first define fitness as diet, exercise, and sleep.
When you’re 20 you can eat four McDonald’s cheeseburgers, drink a gallon of Mountain Dew, get two hours of sleep, and then ride your bike 10 miles across town to a college class. After that, you get out of class, grab some pizza, and then game with your friends all night. Then you’re somewhat tired, so you get six hours of perfect sleep and then you’re once again immortal.
This is the piece that you lose most as you age–the ability to function at your best while not doing the right things.
For a 35-year-old, if you eat 4 McDonald’s cheeseburgers, you’re going to know about it. If you drink a gallon of Mountain Dew, you’re going to regret it. And if you try to do pretty much anything on two hours of sleep, you’re going to wish you hadn’t woken up. Adding the trip across town on a bike and the all-nighter and you’ve firmly entered the realm of fiction.
Diet, exercise, and sleep become increasingly important as you age. If you are 35, or 50, or 65, and you eat like crap and don’t get daily exercise you’re going to feel like death. If you’re 17 and you do those things you will hardly notice. This doesn’t mean you can’t perform at your best as you age; it just means the default state increasingly becomes not doing so.
Naturally, if you were in perfect shape in your 20’s and you maintain that in your 60’s, you’ll be behind in your 60’s. But what’s far more likely is that you were in crappy shape in your 20’s, never noticed, and getting in even decent shape in your 60’s will take you to beyond where you were back then.
Just remember that if you fall off the fitness horse you’ll probably break something.