This boils down to physicality as a modus vivendi.

1. Do you train, "just because"?
2. Do you crave the experience of high physical exertion?
2a Are you grumpy when you don't get it?
3. Does physical exertion bubble towards the top of your priority stack?
3a. Tell me this, folks...do you occasionally delay sex to get out for a spin?
4. Do you quietly react with surprise when you arrive at the top of a long staircase totally recovered while your younger colleagues are winded?
5. Are your colleagues baffled that you would purposely seek high heart rates just for the "fun" of it?
5a. Do you understand the Third of the "Three Types of Fun*"?
6. OK, truth...come clean here ragazzi...are you addicted to endorphins?

Athleticism=High Physicality

* - Three Types Of Fun ? Duct Tape Then Beer