Jennifer Lopez Getting Her Work Mojo Back

A year ago singer, actress, designer and entreprenuer Jennifer Lopez put her busy career on the backburner for her and husband Marc Anthony's newborn twins, Max and Emme.

The twins turned one Feb. 22, and Lopez is ready to go back to work. Getting her J. Lo drive back took a lot of effort, she said today on "Good Morning America," and completing a triathlon six months after she gave birth was a big part of that.

"Your body becomes sort of this temple for the babies," Lopez told Diane Sawyer today. "I needed to do it [the triathalon] to feel like Jennifer again. It was really great for me physically, emotionally, mentally. It got me thinking about achieving again, doing again."

Lopez, who turns 40 in July, has a movie on the horizon -- a romantic comedy called "The Back-up Plan," according to her Web site. In the movie, she plays a single woman who turns to artificial insemination to answer her ticking biological clock.

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She's also raising awareness about pertussis, the potentially fatal disease better known as whooping cough.

Visit www.soundsofpertussis.com to find out more about the vaccine.

Pertussis cases were virtually nonexistent in the United States after a vaccine was developed. Reported cases of whooping cough hit a low of about 1,000 in 1976. That number has been on the rise over the past 30 years, and in 2005, 25,000 cases were reported, according to the Centers for Disease Control and Prevention. According to a CDC study of the disease, Hispanic infants were particularly hard hit by the disease, though there is no clear reason why.

Immunization from the whooping cough vaccine wears off over time, usually between five and 10 years, so adults can spread the highly contagious disease to infants.

Lopez said babies most often contract the disease from their parents, and it can go undetected. "We'll be OK, but it could be fatal to the babies," she said.

The Sounds of Pertussis campaign educates adults about getting a Tdap booster shot, which protects against tetanus, diphtheria and pertussis.