While many people have to work out regularly and really watch what they eat their whole lives, most people are not Martina McBride. But the mother of three, who posed in a bikini on the cover of Shape magazine last year, admits she finally had to start an exercise routine just a few years ago.

"All my life, I had the metabolism where I haven't had to really work out -- until about four years ago," Martina tells Babble magazine. "Things started changing after I had my third baby, and I realized I was going to have to change, clean up my eating and work out a little bit. I'd never worked out before and I really don't like it very much. It's a new thing for me."

The petite singer says she doesn't overdo it, however. "I work out maybe thirty minutes a couple times a week. For me, it's everything in moderation, but if I want cheese fries, if that's what I really want, then I don't deprive myself. I just try to make good choices."

Martina also felt posing in a two-piece swimsuit would be a good example for her daughters. "I started working out a little bit and taking really good care of myself about a year ago," says the 43-year-old. "I thought it was a good way to show that women at every age can be healthy and in shape."

Not only does Martina have a healthy body, but her voice continues to be in great shape, too. The vocal dynamo is currently climbing the charts with her latest single, 'Wrong Baby Wrong.'