When looking back on most athletes after they retire we focus on the prime of their career. That window of time is usually between five and seven years when a particular athlete was at his or her best. Depending on the sport and even the gender, that range of time can vary. Female tennis players rarely compete at their best into their 30's while male professional golfers may just be hitting their stride at that time.

Playing at the highest level of your sport past your prime used to be a need for many athletes who were not paid as well as they are today and if they stopped playing professionally these athletes would not be able to support their families. Now a days professional athletes, if they are smart with their money, can avoid the same financial worries as their predecessors.

Athletes of the past may have had a large financial reason to continue playing for as long as possible, while modern day athletes have the benefit of the latest science and training information to make playing while getting long in the tooth possible. With the knowledge of anatomy and nutrition, professional athletes of today have the information to best take care of their body and help keep it fit and strong for longer so they can avoid injury and stay strong and fit as they advance in age.

There is also career saving and prolonging surgeries that allow players to keep playing longer and if your sport does not outlaw supplements like human growth hormone or steroids than an athlete can outfit a 40-year-old body with the muscle mass, strength and agility of a 25-year-old.

Regardless of the era or the sport or the gender, we as fans cannot help but admire any athlete who can continue to compete at the highest level well after their best before date has passed.

Here is a list of the top 10 athletes who dominated at an old age.

10 10. Jack Nicklaus

Jack Nicklaus in the minds of many is the greatest golfer of all time. Watching Tiger Woods decline over the past few years has only helped to display just how amazing Jack was. The Golden Bear entered the 1986 Masters tournament a 46-year-old man. He had been playing good golf for the previous five years, but had not been able to capture a major tournament win in that time. It was widely thought that at his advanced age his last major win had come and gone. Nicklaus proved the detractors wrong in 1986 and provided us all with a lasting memory of a great champion doing it one more time with his amazing win at the 1986 Masters. What may be even be more remarkable was Nicklaus's run at the 1998 Masters when he finished tied for 6th at the age of 58 and battling an injured hip.

9 9. Satchel Paige

One of the greatest pitchers of all time, he dominated Negro league baseball for years and years before Major League Baseball integrated. When Paige finally got a chance to show his stuff in the big leagues, he was 42 years old, an age when most pitchers are usually settling into retirement. Paige became an all-star in 1952 and again in 1953 at the ages of 46 and 47. Paige played in a time when relief pitchers were seldom used and the notion of a pitch count was limited to pitching until the game was over. With the amount of innings he pitched and his ability to continue to get the best hitters out into his late 40's, Paige's greatest accomplishment may have been striking out Father Time.

8 8. Jimmy Connors

When a tennis player turns 30, it is very difficult to stay at the top. There is so much running in tennis and no true off-season allowing time for recovery, tennis players are constantly playing, practicing and training. They play long matches in extreme temperatures that raise the risk level of exhaustion and injury. At the 1991 U.S. Open, a 39-year-old Jimmy Connors was the sentimental favorite and used the energy of the crowd to make a Cinderella run all the way to the semi-finals. Connors continued to compete into his 40's, routinely beating players much younger than him.

7 7. George Blanda

As a NFL quarterback and placekicker, George Blanda played an astounding 26 years in the NFL. His accomplishment is truly amazing when you think that the average NFL career lasts about two or three years. It wasn't just his longevity in a sport with such a high turnover that made Blanda so great, he also set an NFL record for the most TD passes in a game with seven. In 1970 at the age of 43, Blanda was the runner-up for the NFL MVP award.

6 6. Randy Couture

The UFC is not a sport for the faint of heart. The intensive training and physical punishment that these competitors have to endure while preparing for and then fighting in the octagon is unlike any other sport. The potential for serious and permanent injury is incredibly high so any vulnerability that a fighter may have is frighteningly dangerous. Age could be seen as a vulnerability, but not for Randy Couture who was competing in mixed martial arts main events into his late 40's, maintaining the strength, stamina and quickness that MMA requires.

In perhaps the UFC's most inspirational performance, Couture came out of retirement at the age of 43 to defeat Tim Sylvia via unanimous decision to win the UFC Heavyweight Championship.

5 5. Martina Navratilova

One of the greatest tennis players of all time, her name has come to personify athletic grace and sportsmanship. Navratilova made her first appearance in a grand slam final at age 19 and was still making grand slam finals at the age of 38. In female tennis it seems like there is always a new flashy teenage prodigy that emerges and is competing for titles at 17 and 18 years old, but Martina consistently met each new challenge from following generations of young teenage tennis stars. Even after she decided to retire from singles competition she was still winning multiple championships in doubles and mixed doubles well into her 40's.

4 4. Brett Favre

Brett Favre was the scrappy little QB that could while playing for the Green Bay Packers. He was at the top of his profession because of his unbreakable will to win and shotgun arm that could never be outrun by a receiver down field. As Favre aged, the beard and hair got a little more grey and he seemed to walk with a little slower step, but out on the field he could still scramble and sling that arm back as if he were 25 years old. Favre's accomplishments into his old age are quite something considering how durable he was throughout his career, rarely missing games and taking a mountain of punishment from defensive lineman blitzing for sacks.

Favre had his best season with the Minnesota Vikings in the 2009 season at the age of 40. He threw for 4,202 yards and his best TD-INT ratio in his career, 33-7. He set a career high with a 107.7 passer rating. He led the Vikings to a 12-4 record and an NFC Championship appearance, beating his former Packers twice along the way.

3 3. Nolan Ryan

Nolan Ryan seemed to get better with age. Most pitchers that throw as hard as Ryan did, can't maintain that velocity for too long and without it they struggle to get hitters out. Ryan did maintain his hard throwing ways, as he exhibited freakish strength and radar breaking speed into his 40's. Ryan was able to throw his 6th and 7th no hitters while he was north of 40. Ryan played over a span of four decades and struck out seven pairs of fathers and sons which help show a rare combination of longevity and greatness.

2 2. Gordie Howe

Mr. Hockey as he was known, played in five different decades starting with the Detroit Red Wings in 1946 at 18 years of age and not finishing his career until 1980 at the age of 51 for the Hartford Whalers. In his final year Howe played all 80 games of that schedule and contributed 15 goals and 41 points. At the age of 49 he put up 96 points for the Whalers of the WHA and was putting up over 100 point seasons after the age of 40 and above for both the Red Wings in the NHL and Houston Aeros of the WHA. There will never again be another player who could play at such a high level for as long a period of time as Gordie Howe. How many 40-year-olds can their team and challenge the entire league in scoring...Howe many indeed.

1 1. George Foreman

Today he is known for his big smile more so than for his devastating punching power. George Foreman was an intimidating heavyweight boxer that took out Joe Frazier and battled Muhammad Ali. He was a great heavyweight champion, but his iconic status was achieved when at the age of 45, Foreman reclaimed the world heavyweight title. As he entered the ring at 45, he looked the part of the older man as he was clearly not in the type of condition that his younger self exhibited and never being the quickest boxer, his mobility was reduced even more, to almost a complete stand still. Because of all this, he took a great deal of punishment in that title bout, but absorbed the punishment and wore his opponent down and still having that awesome punching power, he knocked out Michael Moorer to become champ once more.