One of the first counter-arguments as to why MMA is safer than boxing usually involves the fact that there are no standing-eight counts in MMA. But what happens when a guy doesn't get knocked down or finished?
Usually, the result is a ton of brain damage to go along with some speech impediments.
For the guys on this list, it's a miracle that they're still functioning, let alone some of them still competing in MMA today. They emphasize the phrase, "take a lickin' and keep on tickin'."
There are number of guys who could be on this list and I'm sure the comments section will be littered with suggestions as to who should be on and who should be taken off.
The fighters on this list may not have achieved great success in their MMA careers but they're unquestionably worthy of one title, "the toughest man in MMA."
I'm putting these three men on the same slide and although there are a number of guys who could be placed here, these tend to be three of the most common names who share the same traits.
Jeremy Horn, Brian Ebersole, and Chris Lytle have all been involved in quite a few MMA contests. They've all been involved in well over 50 professional MMA fights and even Lytle has never been KO'ed in his professional boxing career.
Horn has only lost via TKO twice and that's with well over 100 professional MMA bouts (known bouts that is) under his belt.
Ebersole has never been TKO'ed and even shaves his hair into an arrow pointing to his chin; begging his adversaries to attempt to do the impossible.
The main reason these three fighters appear on this list is to represent the guys who've competed in countless MMA fights and have extended careers, all without the lights going off upstairs (or in Horn's case, only twice).
Diego Sanchez may not have enjoyed as much success thus far in his MMA career as the others on this list, but man can he take a beating.
Sanchez has been involved in countless wars over the years and has seen his face disfigured on numerous occasions. He was barely recognizable after his contests with BJ Penn and Martin Kampmann.
Those two fights alone make Sanchez one of the most durable fighters in the sport due to the amount of swelling and blood loss sustained by the Jackson's MMA fighter.
Sanchez has been rocked before but he's never been knocked out. The only loss via TKO on Sanchez's record is due to a huge cut opening up after taking a headkick from Penn on the forehead. And that was after taking a beating few men could've survived through four rounds.
"The Dream" hasn't achieved great success in MMA but to not put him on a list like this would be crazy.
Frankie Edgar is a guy everyone loves to compare to Rocky Balboa. And it's a pretty fair comparison.
Edgar has competed at a weight class that's naturally above what he should be competing at for most of his career and it's taken a toll on Edgar's face during some of his contests.
The first rounds of his final two matchups with Gray Maynard were astonishing in that Edgar not only somehow survived but came back to force a draw in their second meeting and win in the rubber match.
Edgar even took quite a bit of damage that wasn't as visible during his match ups with Benson Henderson and Jose Aldo as the two lit up Edgar's leg on numerous occasions.
The former lightweight champion dethroned BJ Penn at 155 pounds and will remain one of the most resilient fighters in MMA history along with one of its most durable.
Mark Hunt not only has some of the heaviest hands in the history of MMA but has also taken shots from some of the heaviest hitters in all of combat sports.
Just think of all the guys Hunt has faced and only a small handful of them have been able to stop the big man with strikes. Melvin Manhoef is the only guy in MMA to finish Hunt while kickboxing greats like Jerome Le Banner and Semmy Schilt are the only two who've been able to stop Hunt in kickboxing.
Hunt may not have the best all-around game for MMA and has only recently achieved any measure of success in the sport but he's undoubtedly one of the toughest guys to finish while standing in MMA history.
One way I can think that perfectly summarizes Antonio Rodrigo Nogueira's ability to take punishment is a "Pyrhic victory." A Pyrrhic victory is one that actually causes more harm than good despite the victory in the short term.
Yes, Nogueira was able to pull off a number of victories after taking a great deal of punishment but we're seeing the effects of taking that punishment can negatively affect your career down the road.
Nogueira's ability to withstand an incredible amount of punishment while still being able to pull off a miraculous victory became commonplace during the Brazilian's run in Pride.
Many MMA fans won't be able to truly appreciate Nogueira's illustrious career or his ability to withstand a vast amount of punishment due to the fact that many were only introduced to him once Nogueira joined the UFC's ranks.
It's a shame because Nogueira literally perfected the art of the comeback with how many come from behind victories appear on his resume.
These two guys have to be made of adamantium. That's the only logical explanation of how they're still fighting, much less still standing.
Mauricio "Shogun" Rua will go down as one of the most offensive-minded fighters to compete but that often meant little time to defend or counter his opponent's offense. That's led to an incredible amount of punishment taken by the Brazilian yet he's only been TKO'ed once in his career.
Sorry but I'm not counting that freak accident against Mark Coleman.
Dan Henderson may not have been in as many bloody battles as Rua but there's no doubt Henderson has withstood his own equal amount of punishment. And not only has Henderson went blow-for-blow with many of MMA's greats, he's done it across numerous weight classes.
Hendo has competed as light as middleweight and as high as heavyweight, all without suffering a KO loss. Just looking at some of the names that Henderson has faced and it's shocking that very few of them were even able to hurt the Team Quest fighter.
For their ability to take as much punishment as they have and for as long as they have, I believe Rua and Henderson deserve top honors on a list like this.