COLORADO SPRINGS, Colo. (AP) -- USA Swimming's membership increased 13.2 percent for 2012-13, the largest single-year spike in the national governing body's history, which was spurred by the success of the U.S. swimming team at last year's London Olympics.
The governing body released its membership numbers on Tuesday.
Membership for year-round athletes is 340,564, while an additional 63,884 non-athlete members bring the governing body's total membership to 404,448 for the period from Sept. 1, 2012, to Aug. 31.
The previous largest single-year membership gain was 11.3 percent in 2009.
USA Swimming executive director Chuck Wielgus says the strong retention rate helps build the sport's foundation.
Led by Michael Phelps, Missy Franklin and Ryan Lochte, the U.S. Olympic swim team won 31 medals, including 16 golds, to account for nearly 30 percent of the total medals earned by all U.S. Olympians in London.