A single flight of stairs

Just watch at the airport. After check in, to go to security, you have to climb  just one single flight of stairs. 

No one takes the stairs, everyone uses the escalator.

Some of them  are people wo  will be using a Stairmaster in the gym under the supervision of a personal trainer. 

Some of them, especially the MNC types, will be participating in  one weekend marathon a year so that they can post it on linked in. 

Some of them will be tracking all their vital parameters through their smartwatch, and asking AI to analyse the results and give them an optimal life plan. 

All of them if asked, will say that fitness is key and functional fitness is more key, since that is the new mantra.

But none of them will climb a single flight of stairs.