Because MMA constantly invokes emotions of every variety, fighters who intend to optimize their skills in the UFC's Octagon must keep their visceral feelings in check.
Strong fighters use potent emotions to realize their potential while the weak allow the same powerful feelings to hinder their development.
Of the 385 fighters signed to the UFC, none can avoid dealing with the highs and lows that accompany emotional health. The fighters who best learn to cope with their passions make it to the top, and the ones who don't, sell themselves short.
For their own good or to their detriment, here are the 10 most emotional fighters in the UFC.
In each of its 17 seasons of filming, The Ultimate Fighter has offered fans and experts an exclusive look at the psyche of top-flight mixed martial artists.
Last season, budding middleweight prospect Uriah Hall not only wowed spectators with a highlight-reel KO of Adam Cella, he also offered a glimpse of the volatile personality that's dictated his career thus far.
Hall let his emotions run wild in the TUF house, and on several occasions, the 28-year-old Jamaican ignited bona fide feuds with housemates over minuscule issues.
Hall repeatedly reminded his housemates of how the painful bullying he was subjected to while growing up in Queens, New York, had scorned him.
In the TUF 17 season finale, a favored Hall let his emotions get the best of him, putting on a disappointing performance and losing to the tournament's youngest winner, Kelvin Gastelum.
Even before his days in the UFC, 32-year-old Chris Leben struggled to maintain emotional stability.
Emotional issues resulted in multiple DUI’s, a pair of failed drug tests and a cluster of other troubling personal problems for "The Crippler."
Leben first got arrested for DUI while on probation in April 2008 and had to serve 35 days in jail.
Less than six months later, Leben tested positive for stanozolol after dropping a unanimous decision to Michael Bisping at UFC 89.
Jake Rosholt then choked Leben unconscious in his next fight at UFC 102, a setback that sparked a three-fight winning streak for "The Crippler" that included wins over Aaron Simpson (TKO) and Yoshihiro Akiyama (triangle choke). Sherdog.com named Leben the 2010 comeback fighter of the year for his efforts following the stanozolol incident.
Another DUI arrest caused Leben to regress in the Octagon again as he suffered a TKO loss at the hands of Brian Stann shortly after at UFC 125.
True to form, Leben responded with an impressive KO of Wanderlei Silva at UFC 132, only to get TKO'd in his next bout by Mark Munoz at UFC 138 in a fight that he tested positive for painkillers.
As emotionally unstable as they come, expect Leben, who's dropped his last two fights, to roar back again—and then later repeat his ruthless cycle.
Akin to Hall, the MMA world got a full dose of Bubba McDaniel's warped emotional state during the filming of season 17 of The Ultimate Fighter.
McDaniel opened up to housemates about his troubled childhood and his ongoing struggles in MMA. The 29-year-old Texan also broke down in tears on several occasions, including after his rear-naked choke loss to eventual tournament winner Kelvin Gastelum.
Following his submission win over Gilbert Smith in his promotional debut at the season 17 finale of The Ultimate Fighter, McDaniel proved that he's a ball of emotions in victory or defeat.
In an interview with MMA Heat, McDaniel had this to say regarding the death of his friend, Jason Hernandez, who passed away just a month before his fight with Smith, and his emotional state heading his promotional debut:
I didn't have the down emotions for this. I actually felt my friend with me when I walked into the cage this time and I felt his push (and) his drive that he would give me before every fight. I felt all that. I don't have a heavy heart right now. I felt like I did him proud and I'm really happy to do that.
He just celebrated his 36th birthday, but Vitor Belfort still represents a perfect illustration of how the proper emotional motivation can help a fighter maximize his or her potential.
An extremely charged up Belfort used a war of words to fuel his psyche heading into his fight with former top middleweight contender Michael Bisping at UFC on FX 7.
"The Phenom" capitalized on the added motivation and scored a TKO win after landing a devastating head kick and several vicious punches to Bisping's jawline early in the second round.
After the bout and during an interview with the UFC's Jon Anik, a revved up Belfort offered up his thoughts on the then pending bout between Chael Sonnen and Jon Jones by saying:
I want to get the belt. Take that punk Chael Sonnen. I don't even know your name. Get out. Dana (and) Lorenzo, take him out. Let me fight Jon Jones. I need that rematch. Take that clown away. Go home. You did a reality show. Go home. Let me fight the real champion. Champion against the champion. Not that clown.
Like Belfort, his counterpart at UFC on FX 7, Bisping thrives off raw emotion, utilizing his own fears and insecurities to always stay on top of his game.
Following his devastating setback to Belfort, which prevented him from getting a shot at Anderson Silva, Bisping refused to take insults from his next opponent, Alan Belcher.
A verbal battle ensued between the two middleweights in the months preceding their fight. When the dust settled, however, Bisping used the media to convey his distaste for Belcher, and for losing fights, and then used 15 furious minutes of fighting inside the Octagon to get his career back on track.
Melvin Guillard experienced two firsts at UFC 150 last August.
Not only did "The Young Assassin" suffer his first career knockout at the hands of former teammate Donald Cerrone, he also missed weight for the first time in his 10-year career.
The setbacks instantly generated heavy emotions for Guillard, marking another downward spiral in the 30-year-old Louisiana native's UFC career.
Guillard blamed a failed pre-fight drug test (cocaine) in 2007 on the death of his father. Joe Stevenson choked Guillard in that bout before Rich Clementi did the same in his ensuing fight.
A supremely gifted athlete with loads of potential, Guillard needs to mimic the acts of Belfort and Bisping and channel his emotions positively if he intends to get back into title contention.
His actions following several fights in his career have exemplified why B.J. Penn simply can't control his emotions.
In his heyday, and following wins at UFC 84 and UFC 107, respectively, Penn celebrated by feverishly licking the blood of opponents Sean Sherk and Diego Sanchez off his gloves.
But in the twilight of his career, and following losses to Nick Diaz and Rory MacDonald at UFC 137 and UFC on Fox 5, respectively, Penn pouted profusely and threatened to retire on each occasion.
A dynamic talent who became just one of two fighters in UFC history to win belts in two divisions (welterweight and lightweight), Penn has always left his emotions out in the open—win or lose.
Chael Sonnen genuinely believed his rematch with Anderson Silva at UFC 148 would unfold similarly to his first fight with "The Spider" at UFC 117—minus the Hail-Mary triangle armbar from Silva, of course.
Perhaps that why Sonnen more resembled a young boy who had just gotten word that Christmas was cancelled than a top-flight UFC middleweight when he got TKO'd by The Spider in the most significant fight of his career.
In an attempt to hide his emotional devastation over the losses, Sonnen continued to perpetuate a pro-wrestling-like persona following his setbacks to Silva.
So following his saga with Silva, "The American Gangster" baited light heavyweight champ Jon Jones into a title fight, again briefly alleviating the awful sensation of defeat.
Jones, however, dismantled Sonnen, sending the 36-year-old Oregonian into yet another state of depression.
Thankfully for The American Gangster, he now has a broadcast career to fall back on.
Like many of his peers on this countdown, former UFC lightweight title challenger Diego Sanchez has experienced tremendous highs and demoralizing lows in his career.
Following his stint on the first season of The Ultimate Fighter, Sanchez joined the UFC and won 10 of his first 12 bouts to set up a showdown for the lightweight belt against Penn at UFC 107.
Penn outclassed Sanchez and ultimately kicked the Jackson's MMA standout in the forehead, opening a massive fight-ending cut.
Known for his enthralling entrances into the Octagon and his non-stop, aggressive style, the emotionally charged Sanchez had to change his nickname from "The Nightmare" to "The Dream" to fully recover from his loss to Penn.
As if the MMA community didn't already know, former Strikeforce champ Nick Diaz reiterated his emotional instability following his loss to Georges St-Pierre at UFC 158.
Initially after hearing the decision being read in St-Pierre's favor, Diaz, just like he did following his previous fight against Carlos Condit, took the liberty to indirectly announce his retirement.
But less than an hour later, Diaz showed up unannounced at the post-fight press conference for UFC 158 and allowed his emotions to run wild by saying:
I could sit here and make a million excuses about why I wasn't ready for this fight, but the only reason why I'm here right now is I want a rematch. I think I can beat [St-Pierre]. That's what I think. I think I may be a better matchup for Anderson Silva, as well, but we'll see what happens. I didn't have a good first round or a good performance tonight. But I carried out a lot of my plan and what I wanted to do. I just think that I could have been a little better prepared for this fight. I think maybe next time if I did get an extra shot, I think that people would try to help me out a little bit.
Although fans can't depend on Diaz's word regarding retirement, they can relay on "The Stockton Bad Boy" remaining the UFC's most emotional fighter. After all, only an emotional mess like Diaz could announce his retirement, and then just an hour later, call out the sport's top pound-for-pound fighter with genuine conviction.