When Should Fighters Retire?

This is a big question that's highly debated in the combat sports community. Because we've got boxers like Manny Pacquiao and Floyd Mayweather who are way past their prime but still competing and fighting for titles at that. We've got MMA fighters like Clay Guida and Jan Blachowicz nearing 40 but still competing or holding titles!

Where do we draw the line though, or should we even draw a line? After Manny's loss the other night many fight fans are wondering if he should retire or at what point generally we should stop expecting our favorite fighters to compete. We've got guys like GSP and Khabib who retire what some would say kind of early, but at the same time these dudes were very hard on themselves in their training - must've saw a decline in their performances and known it was time to hang up the gloves.

Personally I think we should leave it up to the fighter. Look at Blachowicz, the dude is near 40. He's the oldest current UFC champion I believe. The man is still out there kicking butt. At the same time there's fighters out there retiring well into their early or mid 30's. Then you've got guys like Anderson Silva who, step down from the complicated dynamics of MMA to focus on solely boxing.

At the end of the day we should just support our favorite fighters in what they want to do whether it be retire, keep competing, or just go to coaching. It's not up to us, and we shouldn't act like we know any better than the fighters we are fans of. What do you think?