Jennifer Lopez is taking losing the baby weight seriously.

The star was "laid out like a beached whale" when she stumbled across a televised triathlon - and decided that would be a great achievement for a mother of twins.

She tells U.S. fitness magazine Self, "I thought, 'What can I do to make my babies proud?' I think about what they'll think about the year they were born: who I was and what I did.

"It's important to me to set examples for them. I want to lead with my life. I want to say, 'You should do this because I've done it, and I know it makes you a better person and it makes you feel great and sleep better and be happier.'"

Lopez insists her triathlon goal has really helped her get back into shape after giving birth to babies Emme and Max in February - with the help of longtime trainer Gunnar Peterson.

She adds, "Working out and getting back into shape isn't exciting to me but training for a triathlon is. There's a goal at the end of it, something to reach for."

Lopez plans to compete in her first triathlon - a marathon of running, swimming and cycling - later this year.