Money is still on the top of the sport.
For each of these five boxers, age is seemingly just a number.
They have shown an ability to continue fighting at an elite level as they've come to, and in some cases passed, an age in which traditionally fighters begin to see their skills erode.
Contrary to being on the decline, several of these fighters have seemingly improved with age and are still considered amongst the best pound for pound in the sport.
They continue to defy Father Time and are still capable of dominance inside the ring.
Floyd Mayweather has aged slower than most fighters due to his ability to avoid punishment.
Floyd Mayweather Jr. turned 35 prior to his fight with Miguel Cotto in May of last year. It's likely he will see another birthday before he steps back into the ring in the coming months.
Mayweather still remains the single most dominant force in the sport of boxing. He has made a career out of making fellow elite, or at the least very good, fighters look ordinary.
The secret to his success has been amazing reflexes, speed and defense that have allowed him to avoid any sort of serious punishment. It's rare to see him even get hit clean, much less take any significant punishment in a fight.
Until those reflexes and speed begin to fall off a bit, it's hard to see him being any less dominant than he's been throughout his career.
Martinez is a late bloomer who could still dominate virtually any fighter on the planet.
Sergio Martinez will be 38 years old by the time he next steps into the ring to face Britain's Martin Murray in his native Argentina.
But "Maravilla" is one of boxing's rarest commodities—a late bloomer who fully reached his potential.
Martinez was a relative unknown until a string of bad luck in 2009 cost him two deserved victories. A ludicrous draw against Kermit Cintron, followed by a close and controversial decision loss to Paul Williams propelled him to a shot at the middleweight crown.
He won the title by besting Kelly Pavlik in 2010 and has held it ever since. In that time period, he avenged his loss to Williams and absolutely dominated, for all but 90 seconds, the younger and seemingly stronger Julio Cesar Chavez Jr.
More scary for the rest of the middleweight division is that Sergio Martinez seems to be improving with age.
Dinamita finally got his just due when he defeated Manny Pacquiao.
Juan Manuel Marquez, 39, spent much of his career being an elite fighter that no other elite fighters wanted to face. He was just considered too high risk and low reward.
His four-fight, and possibly growing, series of fights with rival Manny Pacquiao finally saw him get a deserved victory this past December.
It was stunning, and brutal and firmly established Marquez as something boxing observers have known for a long time—one of the true elites in the sport.
Even with Marquez turning 40 next year, there is no reason why he won't still compete at this high level should he decide to fight on.
Wlad hasn't lost in nearly nine years.
Wladimir Klitschko, 36, hasn't lost a fight in nearly nine years, and there is no reason to think his reign of dominance will end anytime soon.
There are a few up-and-coming fighters in the division that could possibly pose a threat, but most are untested at this stage and have shown little to indicate they are a ready for this level of challenge.
The younger Klitschko brother has built his dominant reign behind his long jab and impregnable defense that has defended his suspect chin.
Between his jab and cannon of a right hand, it's hard to see many fighters out there who can survive that incoming long enough to land their own shots.
The Cobra will look to establish himself with Andre Ward on the shelf.
Carl Froch, 35, is one of the best super-middleweights in the world and one of the sport's most underrated fighters.
Both of his career losses were close, hard-fought battles against Andre Ward and Mikkel Kessler, respectively, and the Brit will be looking to avenge at least one of those losses this year.
With Andre Ward out indefinitely following shoulder surgery, this will be a great opportunity for Froch to establish himself as the top contender to his crown.
He will seek to seize it by unifying the titles with Kessler sometime this year.