Retirement is equated to a time of rest from labor, but it's undeniable that it also often marks the end of one's most productive income-generating years. If a retirement is properly planned, however, a retiree should be able to live the rest of his/her life comfortably. Unfortunately, in the case of many retired athletes, reckless spending has resulted in career savings being wiped out in a few short years.

In 2009, Sports Illustrated published an exposé on how retired athletes from various sports have managed to find themselves broke despite having earned millions during their careers. 78% of retired NFL players, for example, found themselves in financial distress within two years following their retirement. In just a slightly better situation were retired NBA players, with 60% of them being broke within five years of leaving the game. That, despite the fact that NBA superstars earn the highest average annual salary in sports ($5 million).

Fortunately, not all retired athletes end up turning their lives into sob stories after hanging up their gloves, shoes or helmets. Forbes recently published a list of the highest-paid retired athletes of 2013, and their cases prove that it's within an athlete's control to continue to be profitable, in some cases, even more profitable, after their exits from their sports.

Here are the ten highest-earning retired athletes of last year, arranged according to their estimated incomes:

10. Pelé / Football / 2013 Earnings: $15 Million

With FIFA's World Cup and the Summer Olympics coming to Brazil in 2014 and 2016, respectively, retired football great Pelé suddenly finds himself in hot demand. Despite the fact that it has been almost four decades since Pelé last played as a professional, the International Olympic Committee's "Athlete of the Century" for the 1900s was still selected as Brazil's most influential celebrity.

And as if it weren't enough that "The King" was the best paid athlete in the world in his playing years, with his legendary status today have come numerous lucrative endorsement deals. Pelé is currently under contract with Emirates Airline, Subway, Carrefour, Hublot, Volkswagen, Vivo, Santander, and Procter & Gamble.

9. Greg Norman / Golf / 2013 Earnings: $16 Million

Since wine gets better with age, what's a more appropriate venture for a retiree than a wine estate? That was a question 7-time World #1 golfer Greg Norman probably answered "nothing" to when he partnered with winemakers from Beringer Blass to launch the Greg Norman Estates wineries in the 1990s. That turned out to be a very good business decision as the brand moves around 175,000 cases annually.

Adding further to Norman's income as a retiree are his asset management, eyewear, and apparel business ventures, as well as his endorsements for Club Car, Pacific Links, Cobra Golf, Dow, Sandals, Omega, and Johnnie Walker. The earnings from all those deals are certainly nice supplements to the $15 million in prize money he pocketed while playing golf as a professional from 1977 to 2009.

8. Wayne Gretzky / Hockey / 2013 Earnings: $17 Million

When Wayne Gretzky left hockey in 1999 at 38 years of age, many fans believed he retired too early since he was still setting records at that time. However, Gretzky probably took into consideration that someone nicknamed "The Great One" who is known to be "the greatest hockey player ever" is likely to wield considerable drawing power as an endorser even after retirement. And that's something Wayne certainly took advantage of in 2013.

Already the face of Bigelow, Breitling, Samsung, and TD, Gretzky signed contracts to endorse Upper Deck and Fairfax Capital last year. In addition, Wayne has a booming wine business and even took in $8 million as deferred compensation for his time with the NHL's Phoenix Coyotes.

7. Gary Player / Golf / 2013 Earnings: $19 Million

78-year-old former professional golfer Gary Player made more than twice as much money in 2013 as he did during all of his sixty years as an athlete on the PGA and Senior Golf tours. His main milking cow these days is his golf course design business, Black Knight International. Last year alone, the company generated an estimated $17 million in revenue with more than forty course design projects currently in the works. Added to that amount is the $8 million Player earned from corporate sponsors, which included the likes of SAP, Rolex, and Callaway. Another $5 million was banked from his real estate ventures and licensing deals.

Asked about retirement, Gary passionately opines,

This business of people having to retire from a company when they're 60 or 50 is hogwash. How could you tell me I've got to retire at 78 when I could beat most guys under 40 in a fitness contest? How can you tell me to retire when I'm travelling more than most people that ever lived? And how can you tell me to retire when I'm working on my own ranch mixing cement, carrying poles, and driving a tractor?

6. Shaquille O'Neal / Basketball / 2013 Earnings: $20 Million

When basketball fans see Shaquille O'Neal on his popular TV show "Shaqtin' a Fool", they likely see a former NBA superstar who's lightheartedly and comfortably enjoying the money he was paid throughout his career. What probably doesn't occur to most people is that Shaq is still earning millions each year despite having retired from the game in 2011.

In fact, in 2013, the 4-time NBA champion pocketed an awesome $20 million, mostly from his endorsement deals with Monster Headphones, IcyHot, and Buick, as well as his licensing deals with AriZona Beverage, Zales, and Macy's. Furthermore, more than 100 million pairs of O' Neal's Shaq/Dunkman shoes have been sold worldwide. Of course, Shaq is also paid handsomely for his sports broadcasting work.

5. Magic Johnson / Basketball / 2013 Earnings: $22 Million

When Earvin "Magic" Johnson permanently left basketball in 1996 after coming back from an HIV-positive diagnosis, most people expected him to focus on dealing with his disease, then quietly fade away a couple of years later. Well, he's had other ideas. In fact, in 2013,  the 5-time NBA champion earned millions from a business empire that dabbled in food services and staffing, insurance, and healthcare.

Furthermore, despite selling 105 Starbucks franchises and his 4.5% stake in the LA Lakers in 2010 (which together earned him more than $100 million), he still has an ownership stake with the Los Angeles Dodgers. In fact, in January of 2014, Johnson, along with Mark Walter, purchased the WNBA's LA Sparks after its previous owners decided they could no longer financially support the franchise. With his business savvy, Magic is likely to take in a profit from the deal.

4. Jack Nicklaus / Golf / 2013 Earnings: $30 Million

Jack Nicklaus offered a very interesting view of the golfing career he has had in connection to the life he's currently enjoying as a retiree: "Most people work all their lives so they can eventually stop and go play golf. I played golf my whole life, and when I stopped I went to work."

And with eighteen majors to his name, Jack can certainly command quite a hefty amount when he actually decides to "work". After founding Nicklaus Design nearly 45 years ago, the company has designed 380 courses in 36 countries and 39 US states. In fact, the company currently has 55 projects under way, most of them in Asia.

3. David Beckham  / Football / 2013 Earnings: $37 Million

David Beckham is the most recently retired athlete to make it to this list, his last game as a professional having been played on May 12, 2013. However, his endorsement deals haven't dried up. Instead, Beckham has since signed several new contracts, including those with Asian companies: the Chinese Super League, China Auto Rental, and Sands. Those were additions to his already existing contracts with Samsung, Sainsbury's, H&M, Coty, and Adidas.

David is set to make even more money as he is currently laying the foundation for a new Miami-based MLS team, his option to purchase a franchise being one of the perks included in his 2007 MLS signing contract.

2. Arnold Palmer / Golf / 2013 Earnings: $40 Million

Retired American golfer Arnold Palmer, won seven majors and $1.9 million in prize money throughout his career with the PGA Tour. But today, at 84 years of age, he's making even more than he did as an active athlete, 2013 being his most profitable year yet.

Much of the $40 million he earned last year was from the highly successful Arnold Palmer line of drinks manufactured by AriZona Beverage. In fact, the drinks attributed to Arnold constitute roughly 25% of the company's revenues. He's also earned a fortune from licensing his name in Asia, where there are at least 400 freestanding "Arnold Palmer" sports stores.

1. Michael Jordan / Basketball / 2013 Earnings: $90 Million

When you're widely considered to be the greatest basketball player of all time, it's likely that you're going to be in a position to make some good money despite having been retired for a number of years. Michael Jordan certainly accomplished that in 2013, when sixteen years after his last NBA game, he earned close to the $94 million he was paid for playing fifteen seasons in the league.

How did he do it? Most of his 2013 earnings were from Nike's Jordan Brand, which constitutes more than half of the U.S. basketball shoe market. And then there were his endorsements, including those for Five Star Fragrances, Novant Health, 2K Sports, Upper Deck, Hanes, and Gatorade. Add to that earnings from owning a car dealership, seven restaurants, and 80% of the Charlotte Bobcats, and you have the formula for what made Michael Jordan the second highest-earning athlete of 2013 behind only boxer Floyd Mayweather, Jr.