J.Lo at 40: How a Diva Was Made!

In 40 photos, see how the birthday girl (on July 24) went from Jenny from the Block to superstar

FROM WORKOUT TO WORKING IT

Lopez begins her day on Sept. 14, 2008 by running, swimming and biking in the 18-mile Nautica Malibu Triathalon, which she finishes in 2 hours, 23 minutes and 28 seconds. But instead of spending her night with her feet up, she slid them into heels – and put on a flowing Marchesa gown – to step out in New York for a surprise party for Anthony. "I told him it was such a busy weekend, that I might not be able to do anything [for his birthday]," Lopez says of how she pulled off the surprise.