Chael Sonnen might not carry himself in the most idealistic ways, but even his most vocal detractors have to admire his self-confidence and work ethic. Though he does have his weaknesses inside the cage, namely his infamous submission defense that has plagued him in eight of his 11 career losses, Sonnen has a drive unlike any other middleweight in the world.
In his first shot at dethroning 185-pound champion Anderson Silva, Sonnen put his foot on the gas for the better part of five rounds until he was caught in the Brazilian's triangle choke. In addition to showing improved submission defense, Sonnen will undoubtedly be looking to dictate the pace of the fight once again in his rematch with Silva at UFC 148 on Saturday.
With all title fights being booked for 25 minutes of action, great conditioning is a must for fighters who have hopes of becoming and remaining UFC champion. Here are the fighters in each of the UFC's eight divisions who have the most in their gas tank.
Cain Velasquez is widely regarded for having better cardio than any other heavyweight in the world.
However, his spot as the most well-conditioned big man may no longer be as safe as it once was, as champion Junior dos Santos has showed he can also go at least three rounds without losing much of a step.
Though Velasquez has only gone the distance once in his MMA career, he has never showed any signs of tiring despite the nonstop aggression he displays in almost all of his fights. When he attempts to reclaim his belt from Dos Santos later this year, Velasquez will be looking to avoid another early knockout and, instead, take the Brazilian into deep waters.
In a sport that is still evolving, light heavyweight champion Jon Jones has proven—at least inside the cage—that he is about as flawless as a fighter can be. Yes, Jones is still improving his striking, but his insane reach for a 205-pound fighter and exceptional wrestling make any holes in his stand-up game appear non-existent.
Jones' technique in almost all areas is great, but it is his athleticism and conditioning that put him on a whole other level. Because he has defeated his opponents with such ease, it seems few have taken the time to recognize that Jones has already erased any questions that might arise about his gas tank.
Two of Jones' past three bouts have gone into the championship rounds, yet he has shown little fatigue and even appeared to turn up the pace for a fourth-round stoppage of former UFC champion Quinton Jackson.
Love or hate the person he is outside of the cage, it's hard not to respect the Chael Sonnen who will step into the Octagon across from Anderson Silva on Saturday night.
He may have some holes in his game that he has been unable to fix, but Sonnen is relentless in his attack and only knows one direction—forward.
For those indifferent toward the ground game, Sonnen's fights may not be the most entertaining, but he has gone the distance 16 times during his career and never stopped working in any of those bouts until the final horn sounded.
It's predictable, but Sonnen is going to try to do to Silva exactly what he was able to do through the first four rounds of his first meeting with the middleweight champion. Sonnen will look to press the action and put Silva on his heels before taking the fight to the ground and keeping it there.
If there has been an athletic specimen more impressive than Jon Jones to come through the ranks in MMA, it would be welterweight champion Georges St-Pierre. In becoming widely regarded as the best wrestler in the sport despite lacking a wrestling background of any kind prior to his MMA training, St-Pierre may be as well-rounded as a fighter can possibly become.
Much to the dismay of those thirsty for finishes, St-Pierre's past six fights have reached the championship rounds. While he has been criticized for his lack of finishing ability in those bouts, St-Pierre's ability to control opponents for five full rounds without fading has to be admired.
In terms of conditioning, there may not be a fighter in the world who can match Clay Guida. Sure, his spot on this list will come into question after his lackluster performance against Gray Maynard, but Guida has a gas tank unlike any other.
Guida uses more energy walking to the Octagon than some fighters use in an entire fight, and his head movement alone would cause most competitors to tire in the later rounds of a fight. Guida's conditioning is what makes him such a tough opponent for any lightweight, so that is why it was so frustrating for many to watch his lack of aggression against Maynard.
As we work our way to the lighter weight divisions, it becomes harder and harder to give one fighter a decided edge over the rest, as almost all of these smaller competitors can compete at a fast pace for three rounds without much difficulty.
Still, Mark Hominick separated himself from the pack with his fifth-round performance against featherweight champion Jose Aldo in April 2011. After four strenuous rounds, Hominick still had enough left to put a beating on the Brazilian in the final frame, though he couldn't finish the fight and came out on the losing side of a decision.
Since his fight with Aldo, Hominick has lost two more fights, extending his losing streak to three. However, none of Hominick's UFC losses have had anything to do with his conditioning.
Dominick Cruz's footwork may be unorthodox, but it frustrates and tires opponents to no end and is a large reason why he has already become recognized by some as the best bantamweight fighter of all time.
Despite his perpetual motion, Cruz has been able to go five rounds with Demetrious Johnson, Urijah Faber, Scott Jorgensen and Joseph Benavidez without appearing fatigued in the later rounds of those bouts.
The flyweight division could not have entered the equation at a better time for Demetrious Johnson, who was coming off of a unsuccessful bid for the bantamweight title when the UFC decided to put together a 125-pound tournament to decide their first flyweight champion.
After two closely contested three-round fights, Johnson eventually earned a spot in the UFC's first-ever flyweight title fight, in which he will compete against Joseph Benavidez later this year. Benavidez also has great conditioning, so the bout could provide a chance for him to prove Johnson's spot on this list wrong.