Whether it's out of economic necessity or simply the need to be needed — or at least not bored — more and more Americans over the proverbial retirement age of 65 are continuing to work, either in their longtime careers or in new endeavors. The more fortunate, and moneyed, among us — such as sports celebrities — are also choosing business and investment activities over relaxation in what might have once been their retirement years. Instead, they prefer to launch, for example, new ventures or to move up from playing into management and ownership.

Lifestyle website SportsCheatSheet.com recently ranked the Top 10 "retired" athletes, based on data from Forbes. According to Forbes research, the 14 top-earning athletes in 2015 raked in a combined $444 million in income from "salaries, endorsements, licensing, speaking and appearances, golf course design, book deals and partner distributions." CNBC.com shares the SportsCheatSheet.com/Forbes findings in the following slide. (First things first: You probably haven't earned the tens of millions these sports legends have, so remember: It's critical you manage the retirement income you do have coming in as if it were a paycheck.)

— By CNBC.com's Kenneth Kiesnoski
Posted 18 February 2017
Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Basketball player

Current business interests: Real estate, television, staffin/insurance services, sports franchises.

2015 earnings: $18 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Pro golfer

Current business interests: Celebrity endorsement, golf-course design

2015 earnings: $19 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Race-car driver

Current business interests: Transportation services

2015 earnings: $20 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Basketball player

Current business interests: Investing (stocks, startups), real estate, TV/film/entertainment, music, sports franchises.

2015 earnings: $22 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Pro golfer

Current business interests: Golf-course design, golf instruction (print/video), celebrity endorsement.

2015 earnings: $26 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Football player

Current business interests: Sports franchises, food services

2015 earnings: $30 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Basketball player

Current business interests: Food services/restaurant franchises.

2015 earnings: $32 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Pro golfer

Business interests: Golf-course design, real estate (golf courses/resorts), food/beverage services.

2015 earnings: $40 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Soccer player

Current business interests: Real estate, fashion, entertainment, celebrity endorsement

2015 earnings: $65 million

Sources: SportsCheatSheet.com and Forbes.com

Former sports career: Basketball player

Current business interests: Sports franchises, fashion/apparel, celebrity endorsement.

2015 earnings: $110 million

Sources: SportsCheatSheet.com and Forbes.com