Straight from a wetsuit into an evening gown! Jennifer Lopez was dressed to the nines and looking refreshed out in New York City last night, throwing husband Marc Anthony a birthday party on the same day she completed her triathlon in Malibu. Looks like the foot injury that made her bail on judging the Project Runway finale really isn't slowing her down any — though there are other rumors as to why she pulled out. Jennifer has long been planning this big 40th b-day bash for her husband, which included a costume change during the night celebrating with their friends including Brooke Shields, Donatella Versace, Kimora Lee Simmons, and more. All nanny-free, of course. If you're inspired by Jennifer, get some motivation and training tips here.