What keeps Britney Spears fit?

At 33, singer Britney Spears is very particular about maintaining her toned physique and she looks like she's in the best shape of her life.

The mother of two recently opened up about her workout routine and diet habits, which have evolved with the changes happening to her body as she is ageing, reports contactmusic.com.

Spears has spoken about it in a new edition of 2015 issue of Women's Health, the cover page of which features her flaunting her lean stomach and tanned physique in a revealing bikini.

"After I had Jayden, it was real easy for me to get back in shape. But five years later, I started noticing changes in my body. My hips are a little bit wider because I've had kids. So it was crucial for me to be continuous with my exercise," she said.

So how does the multi award-winning singer maintain such a healthy looking figure?
"Dancing is a great cardio workout," she said. "Tough and fun at the same time."

And when it comes to building up a sweat, Spears opts for high intensity workouts and healthy dietary plans.

"I like my workouts to be effective in a short amount of time. I start with 20 minutes of intense cardio -- usually running -- move on to light free weights, body-weight exercises such as pushups, squats, and situps, then finish it off with a stretch," she added.