Age catches up with everybody. Even with the most expensive plastic surgery performed by the best plastic surgeons, age inevitably takes its toll. Aging changes many things. It changes the way we think, it changes the way we act, and it changes the way we look. For some people, age creeps up slowly while others seem to be stricken by it almost overnight. Some people, like Terry Bradshaw for instance, aged relatively early while others are fortunate enough the hold onto their youthful looks well into maturity.

It can’t be helped that the vast majority of people look much different when they are 40 than they did when they were 20. Take professional athletes for an example. Many of them come out of college in top physical form. They have youthful skin, full heads of hair, and a sparkle of confidence in their eyes. After several years of pushing themselves to the limit, they may still be in top physical form, but most lose their youthful look and their full heads of hair. While enjoying their retirements, they let themselves go physically. Charles Barkley is an excellent example of this, although if you compare him now to the Charles Barkley that hit the basketball court as a rookie, you can still find many similarities. He’s just a heck of a lot larger. Here are 15 retired pro athletes who look nothing like they used to.

15 15. Brett Favre

When he was drafted by the Atlanta Falcons in the second round of the 1991 NFL draft, Brett Favre was a fresh face kid out of Southern Mississippi. He was never given a chance to thrive in Atlanta and was quickly shipped off to the Green Bay Packers where he quickly supplanted Don Majkowski during the 1992 season. The rest is history. Favre went on to become one of the greatest quarterbacks ever. Over his 20 year career, spent mostly in Green Bay, Favre was an eleven- time Pro Bowler and Super Bowl champion who left a permanent mark on the game with his several records. By the time he packed it in following the 2010 season, Favre was a sure-fire Hall of Famer. He was also a grizzled old man with gray hair and a face like an old catcher’s mitt. Despite the change in appearance, Brett Favre remains in great shape to this day.

14 14. Maradona

Diego Maradona enjoyed a very long and illustrious career that spanned nearly two decades. Known for a high level of skill and competitive spirit, Diego thrilled fans everywhere he went. With his ball control skills, Maradona could make opponents look like pylons as he deked them. He also had the ability to make his teammates much better.

His playing days ended in 1997. He was not nearly successful in managing as he was a player. He also had little success keeping himself in shape. He is now better known for his erratic behavior, history of drug abuse, and obesity. The one-time specimen of fitness who was blessed with exceptional athleticism and endurance is long gone. His only remaining a recognizable feature might be his lush head of hair. He is thought to have weighed up to 280 pounds before undergoing gastric surgery in an attempt to shed some of the excessive weight.

13 13. George Foreman

With bulging arms and a body built as solid as a rock, George Foreman was one mean fighting machine. Known more for his devastating punching power than his stamina, Big George pummeled his way to a 76-5 record during his career which spanned from 1969 to 1997. The ex-Heavyweight Champion won an impressive 68 bouts by knockout. He is also living proof that a man who is far past his prime can be an incredible force. He found a lot of success after coming out of retirement at the age of 45.

George is still a big man, but his intimidating snarl has been replaced by a friendly wide smile. His chiseled frame has given way to the rounded physique and it has been years since we have seen his full head of curly hair. Still, the 67-year-old boxing icon looks like he could give any young punk a good butt-kicking.

12 12. Sammy Sosa

Over his 18 seasons in the major leagues, Sammy Sosa was known for his bright smile and generally pleasant personality. The slugger batted .273 over the course of his career. He also had a whopping 609 home runs and hit 243 of those dingers during a hitting spree between 1998 and 2001. It was also in 1998 that Sammy Sosa slugged it out with fellow steroid enthusiast Mark McGwire in a historic chase for the home run title. Following the 2001 season, Sammy’s numbers went into sharp decline. Slammin’ Sammy’s long career came to an end following the 2007 season. The revered long-baller looked like a shoe-in for Hall of Fame, but his legacy was tainted when he was linked to steroid use.

The Sammy Sosa of today bears little resemblance to the Sammy Sosa that broke into the major leagues with the Texas Rangers. While he still maintains his bright smile, he has taken on a very pale appearance.

11 11. Barry Bonds

Barry Bonds is the poster child for Major League Baseball’s steroid era. His well-known use of steroids and human growth hormones have tainted the monstrous numbers that he put up over his 22-year career. It was clear from his early days with the Pittsburgh Pirates that Bonds was blessed with exceptional athletic ability and was destined for greatness. It was also clear that he had a huge ego and was not the easiest person to get along with. He clashed with teammates, coaches, and fans as well as the media. Barry Bonds was quite likely the most polarizing baseball player since Ty Cobb.

One would think that Barry Bonds and his 762 home runs would be quick to be selected into the Hall of Fame, but it appears that a former slugger is in for a long wait. Whether or not Bonds’ stunning physical transformation is entirely due to steroids is debatable. The fact that his appearances changed so much since his rookie year is not debatable.

10 10. Roberto Duran

Roberto “Hands of Stone” Duran is one of the most famous names in boxing history. With an incredible record of 103 wins and 16 losses, the Panamanian puncher terrorized opponents between 1968 and 2001. Of his 103 wins, 70 were by knockout which puts him with some very exclusive company. He is a member of both the World Boxing Hall of Fame and the International Boxing Hall of Fame.

In the years since his retirement, Roberto has enjoyed stints in television, music, and is a brand ambassador for Panama Blue bottled water. It also appears that Roberto’s been enjoying a lot of time at various all-you-can-eat buffets. His once chiseled build that featured muscle on top of muscle has morphed into the bloated physique which features chins underneath chins. That’s not to say that he still couldn’t flatten you with a devastating hook. He just needs to say “no mas” at mealtime once in awhile.

9 9. Nate Newton

Sometimes, not resembling your younger self can be a good thing. Such is the case with ex-NFL guard, Nate Newton. Newton, who had his most successful years playing with the Dallas Cowboys, weighed in at about 320 pounds during his playing days. After his career ended following the 1999 season, Nate ballooned to an estimated 411 pounds. His post-football life was also marked by a couple of high-profile drug arrests. These arrests resulted in him being handed a 30-month prison sentence.

He has since turned his life around and no longer dreams of being the biggest marijuana dealer in the world. He is also made some shocking physical transformations. He underwent a vertical gastrectomy in 2010 which resulted in an incredible loss of weight. As of late 2010, Nate had returned to his high school weight of 220 pounds. Nate’s success story has inspired many and we couldn't be happier for him!

8 8. John Kruk

Ex-Major Leaguer John Kruk enjoyed a productive but short career. He spent his best years with the Philadelphia Phillies between 1989 in 1994. Despite the rugged exterior, Kruk is generally soft spoken and has a very good sense of humor. He is also known for the way he retired. During a game against the Baltimore Orioles on July 30th, 1995, Kruk reached first base on a single. He retired on the spot as he stood on first base. He finished his career with a .300 batting average and 100 home runs.

Since his retirement, John has written a book, dabbled in coaching, and has enjoyed a successful career in broadcasting. He also looks nothing like he used to. He’s one of those guys you look at and say to yourself “He looks familiar but I can’t place the face.” He still has the facial hair and an easy-going demeanor, but he is much bigger.

7 7. Bobby Bonilla

Bobby Bonilla made many stops along the way during his Major League Baseball career. He, along with Barry Bonds and Andy Van Slyke, were the backbone of a potent Pittsburgh Pirates lineup in the early 1990s. His career was a roller-coaster ride of ups and downs both on and off the field. He actually once called the press box during a game to complain about an error that they charged him with. His relationship with fans, coaches, and media alike was tumultuous.

Following the 1997 season in which he batted .297, Bonilla’s numbers plummeted. After 15 seasons in professional baseball, the enigmatic veteran called it quits. It would be hard to tell that the present version of Bobby Bonilla is the same guy that played for the Chicago White Sox in 1987. He appears to be enjoying life as he continues to collect those big paychecks care of the New York Mets.

6 6. Bartolo Colon

One of his early baseball cards lists Bartolo Colon’s weight at 185 pounds. A lot has changed since then. He has racked up 226 wins against 158 losses in an incredible career that has spanned 19 seasons. The 43-year-old workhorse is well traveled having played on eight different teams. He has not let his weight or his age get in the way of longevity. Currently listed at 285 pounds, Bartolo is playing some of the best baseball of his career with his current team, the New York Mets. Despite such a long and successful career, that Colon is still in search of a World Series championship.

If you were to place a Bartolo Colon rookie card beside a more modern card you would be shocked to know that they’re the same person. Of course, aging 20 years and packing on 100 pounds will do that. Many baseball fans are hoping that Bartolo can finally win his ring.

5 5. Mike Tyson

Maybe it’s the noticeable paunch, or the little mustache, or even the tattoos on his face. Maybe it’s the combination of all three. Whatever it is, the Mike Tyson that you see today looks nothing like the Iron Mike who made opponents tremble in fear during his heyday. While his ripped physique has turned pudgy, he still looks pretty menacing. He definitely looks better than he did when Lennox Lewis beat him to a bloody pulp in 2002.

Looking at Mike Tyson today, fans can be assured that his fighting days are over. There will be no George Foreman-like comeback. Having just turned 50, the best that Tyson fans can hope for is that he stays out of trouble and finally finds happiness. Despite a few good beatings, substance abuse, and a well-publicized stint behind bars, the former champ looks no worse for wear. Like many aging ex-athletes, he just looks different.

4 4. Tonya Harding

“Why? Why? Why?” Nancy Kerrigan cried as she grabbed her damaged knee following one of the sporting world’s most infamous assaults. Nancy Kerrigan and the rest of the sports world were shocked to find out the answer. Former figure skating champion and two-time Olympian Tonya Harding became the center of controversy after her ex-husband and bodyguard hatched a plan to eliminate Tonya’s competition. While she denied any knowledge of the plan, Tonya became one of the most despised figures on the planet. The attack on Nancy Kerrigan marked the beginning of Tonya Harding’s tragic, yet entertaining downward spiral. She was banned for life from the USFSA and her figure skating career was over.

Tonya has gone through many changes since then. Boxing and wrestling are just a few of the things that Tonya has participated in during her post-figure skating career. While maintaining slight celebrity status, Tonya is better known these days for her excessive weight gain which has left her unrecognizable from her former self.

3 3. Mike Scioscia

Mike Scioscia has been a fixture in Major League Baseball since 1980. In his 13 years as a catcher for the Los Angeles Dodgers, Scioscia was a World Series winner twice and a two-time All-Star. He was 6’2” and carried his 200 pounds well in his athletic frame. Unfortunately, his playing days ended a little prematurely after he was unable to bounce back from a torn rotator cuff. This did not put an end to his baseball career however. He transitioned into a coaching role with the Dodgers before becoming the manager of the LA/Anaheim Angels. He also transitioned from being a relatively fit man to becoming a rotund and gray-haired codger who looks like he need to have his ball caps custom made to fit his larger head. His looks have changed dramatically since his playing days and fans can expect him to go through more physical changes as he continues his successful managing career.

2 2. Paul Gascoigne

For a guy who is only 49-years-old, ex-midfielder Paul “Gazza” Gascoigne looks more like an aging rock star than an aging ex-athlete. His gray hair and rubbery face are a far cry from the youthful look he possessed when he was patrolling the pitch during his playing days. Of course, Gazza lived like a rockstar. He developed addictions to alcohol and drugs which he still battles to this day. The hard lifestyle has done its damage to the guy who once sported a solid frame, a healthy glow, and a full crop of hair.

Today’s Paul Gascoigne appears haggard with his slicked-back and ebbing gray hair. He has exhibited episodes of bizarre behavior such as his appearance at an armed standoff between police and Raoul Moat in July of 2010. His friends, family, and fans hope that whatever demons are plaguing the ex-soccer star can be exorcised before he takes a turn for the worse.

1 1. Caitlyn Jenner

Bruce Jenner was once an Olympic Gold Medal winner whose performance in the decathlon made him a national hero and the face of Wheaties cereal. He was on the cover of several magazines including Sports Illustrated, Gentleman’s Quarterly, and Playgirl. He was also the spokesman for several other products such as Minolta and Buster Brown Shoes. In short, Bruce now identifies as Caitlyn and has become a television personality, a spokesperson for the LGBT community, and a sort of symbol for the modern LGBT movement.

Even before the full transition, Jenner’s appearance had changed enough to warrant inclusion on this list. Rumors of plastic surgery were rampant. While it might be somewhat of a surprise for those looking from the outside, she is happier, more comfortable with herself and we're very happy for her!