You'll here this term a lot. Online, at gyms and fitness centers, from doctors and therapists. And at first blush it sounds right. Who wouldn't want their fitness to be functional?
But there's an odd redundancy in this. If you're fit, truly fit, you are, by definition, functional. If you do lateral raises and leg presses - movements with no corollary in real life - if you're single physical skill is putting your feet behind your head or if long, slow runs on a treadmill are your only "thing" you are, then, not Fit.
Fitness was long ago defined by your capacity in 10 fundamental aspects; endurance, stamina, speed, power, strength, agility, balance, coordination, flexibility and accuracy. You're as fit as you are competent in all 10 of these capacities. Not one or two, all 10. Being able to run 3 miles in 20 minutes but having a 45lb deadlift doesn't cut it.
This definition neatly satisfies all the normal and most of the unusual circumstances you'll encounter in life; moving furniture, carrying groceries, pushing a stalled car, helping someone off the floor, running after a cab, bus or Uber, escaping zombies, climbing into or out of a high window and jumping to the ground...you know, regular everyday stuff.
Now, don't get too bogged down about whether a particular movement is especially functional (battle ropes, anyone?), pay more attention to your overall activity choices. Are you doing lots of different, fun things that you enjoy? Do you break a sweat? Do you feel better when you're done than when you started? If so, you're on your way to being a pretty useful human.
If you want to get really good and useful, of course, you come to us. It's what we do. There's lots of time to practice zombie evasion on your own.