Meeting up with Good Morning America's Chris Cuomo in Central Park this morning, Jennifer Lopez, who gave birth to twins Max and Emme not so long ago, opened up about her plan to get back into shape by training for a triathlon to take place on September 14.

The triathlon is set to take place in Malibu, and the singer and actress will have to run, bike, and swim in order to raise money for Children's Hospital in Los Angeles. According to the website for the 2008 Nautica Malibu triathlon, the course consists of "a half-mile ocean swim, an 18 mile out-and-back bike course, and a 4-mile out-and-back run course."

Most recently declared the most inspiring woman by Self magazine, Jennifer Lopez is one busy woman. The 39-year-old triple threat revealed she had the idea of entering a triathlon when she was 8 months pregnant. She said she saw one on TV and thought to herself "I can do that…maybe I could do that this year."

Diving into details and challenges about her fitness regime, Lopez said, "You have to start slow and give yourself time," adding that, "I'm always challenging myself and seeing what I can do."

The hardest part of her training, Lopez admitted that it's swimming, "Swimming is a killer," she said, "I'm not going to lie." The singer said training is fun and challenging but admitted she’s scared she might not be able to finish. Self magazine editor Lucy Danzinger, who helps Lopez with her training, emphasized the importance of setting goals and said "if you have a goal, you can reach that finish line."

As for working out and having time for her children, Lopez said that she has a full setup at home with a stationary bike and treadmill and that she does about an hour to an hour and a half a day. Her husband, Marc Anthony, is supportive and helped set up her workout room.

Now more than ever, roughly one month until the competition, Lopez said she's making time for her workouts. And she's not just doing it not just for personal or health reasons: She's raising money for Children's Hospital Los Angeles.

Speaking about the biggest change in her life, becoming a mother, Lopez, who revealed she loves taking care of her babies by herself without any help from nannies, said the twins are doing "great" and "amazing" and that they sleep through the night and that they "go to bed around 9/9:30 and get up around 6:30/7:00."

Regardless of how much she enjoys spending time with her children, Lopez said she's currently looking for a nanny. "We actually just tried somebody out last week when Lucy was there, it was her first day, because I will be going back to work to do a film later in the year, so I’m trying to find somebody… We’ve been doing it [caring for the twins] by ourselves and we love it."