San Francisco 49ers linebacker Chris Borland, center, during an NFL football game in Santa Clara, Calif. Borland announced that he will retire after just one season to protect himself from brain injuries.
Marcio Jose Sanchez/AP
Daina Bouquin competes in the first U.S. Winter Swimming Championships on Saturday in Lake Memphremagog near Newport, Vt. The event drew swimmers from around the world to race in icy water that was below 32 degrees F.
Herb Swanson for NPR
Kentucky's Aaron Harrison and coach John Calipari watch from the sideline during the second half of an NCAA college basketball game against Mississippi on Jan. 6. Kentucky won 89-86 in overtime.
A man watches sports broadcast on screens at a sports book owned and operated by CG Technology in Las Vegas. CG Technology is asking the Nevada Gaming Control Board to allow betting on the Olympics.
NASCAR Sprint Cup Series driver Jeff Gordon, left, says he won't race full-time after the 2015 season. Here, Gordon shakes hands with long-time team owner Rick Hendrick last year.
Jeff Siner/MCT /Landov
A sculpture at Britannia stadium in the English city of Stoke-on-Trent commemorates the Christmas Truce, a legendary soccer game played between German and British troops in December 1914.
Members of the St. Louis Rams raise their arms to protest the grand jury decision in Ferguson, Mo., before a game last month. The players faced a backlash from St. Louis police and have been asked to apologize.