Which makes football an unlikely lifetime sport?
high physical impact
required cardiovascular health
prohibitive equipment cost
required hand-eye coordination

High physical impact: Would seem like it but most likely not.  Physical impact can get you out of the game for awhile but normally you can get back in.
Required Cardiovascular health: You do need to meet standards but sometimes you can keep these under control or you flat out dont go in, again would seem like it. is possible.
Prohibitive equipment cost: Nah. Im made to watch a lot of football and this wouldnt be it
Require hand-eye coordination: Nah. this can be fixed with training. I have horrible hand-eye coordination and did when i was younger but i still played football when younger

Now that i gave some explanations I would say A: Physcal impact. Football can be a dangerous sport and you can get badly injured playing it . This is the most likely cause of football being a lifetime sport.

The answer is keep records