The most powerful athlete in U.S. professional sports? The would be LeBron James, and for more than his powerful build.

The 2013 Bloomberg "Sportfolio" Power 100 has the Heat forward at the top of the class, after being ranked fourth in the previous ratings.

According to the Bloomberg Sports website, the rankings were compiled with 50 percent of the ranking based on "on-field attributes" and 50 percent on "off-field attributes."

The list was limited to "professional athletes playing in the United States," with coaches, executives, owners, agents, and retired athletes not considered.

Beyond James and Bryant, the next highest-ranking NBA players on the list were Kevin Durant (11th) and Heat guard Dwyane Wade (25th).

Heat center Chris Bosh, the third member of the team's Big Three, was not on the list, nor were any members of the Miami Dolphins, Miami Marlins or Florida Panthers.