IMAGES: Hottest celebrity bodies 2013!

Fitness Magazine has compiled a 'fit list' of the stars with the best bodies -- take a look.

As Fitness magazine rightly puts it, 2013 has been a year of 'quite a few OMG post-baby bodies, weight loss wonders and a new crop of A-list abs'.

Think Penelope Cruz, Christina Aguilera and Allison Williams and you'll know what they mean.

In the following pages, we bring you the list from the magazine's latest issue, intended to provide you with that much-needed push to hit the gym.

We start with number:

13. Carrie Underwood

The country singer, known as much for her voice as for her legs, is your typical gymspiration model.

Carrie Underwood stays in shape by running, kickboxing and putting those resistance bands that are usually stacked away in our storage bins to real use.

What's more? She keeps a food journal!

All that and more put Underwood at number 13 of the list of fittest celebs.

At number 12 is Paula Patton.

So what goes into the making of this hottie?

Earlier this year, celebrity trainer, Jeanette Jenkins, revealed how Paula Patton stays in shape. The yummy mummy warms up with a two-mile (yes!) run and follows it up with numerous squats, pushups, planks etc.

Patton also does yoga, Pilates and hikes and power walks and spends over two-and-a-half-hours working out six days a week.

Gossip Girl star Blake Lively apparently leads such an active lifestyle that she simply doesn't workout to look this good.

Like many models we know of, Lively credits her gorgeous figure to high metabolism.

Now that's something we all could kill for, couldn't we?

The Roar hitmaker came ten in the list of fittest celebs. Like all good girls, Katy Perry watches what she eats and goes biking and hiking whenever possible.

Best-known for her role in Girls, Allison Williams has been whipping herself into shape with celebrity trainer Reggie Chambers. Her workout includes core workout and boxing besides Core Fusion Barre and SoulCycle classes.

Exactly how many kilos did Christina Aguilera lose? The number varies from 30 to 80 pounds. Fitness magazine puts it at 49 pounds -- that's a little over 22 kilos!

The popstar who swore off alcohol and got a more active lifestyle, was eighth in the list of the fittest celebrities of the year.

Amanda Seyfried who plays the porn star Linda Lovelace didn't have to workout at all to because 'if I stopped eating, I would look gross'.

So Seyfried simply decided to continue with what she'd been doing all along -- eating healthy and being vegetarian.

Best known for her role in Sienfeld, Julia Louis-Dreyfus who is now 52 only seems to be getting fitter with age. She's confessed to being 'addicted to the post-workout high'.

Her fitness regime includes hiking, toning exercises and running an awful lot on the treadmill.

Scarlett Johansson has confessed that she works out 'like a guy' which means there are good chances you'll catch her weight lifting and doing core exercises rather than cardio.

This is when she isn't preparing for a role that needs her to wear skin-tight outfits like in Avengers and Iron Man movies.

Still wondering she's the only star to be named Esquire's sexiest woman alive twice in the magazine's history?

Kerry Washington was named People's Best Dressed of 2013. The soon-to-be-mom swears by Pilates and, well, eats healthy. Sound simple, doesn't it?

Will she ever stop looking stunning? Apparently not! Close to turning half a century old, Sandra Bullock has a figure that can give women half her age a run for their money. She gets that enviable figure from simply doing what your instructor has been telling every single person who walks into his gym -- a combination of cardio and strength training exercises for an hour every day.

For someone who has been threatened to be fired if she didn't lose weight, Jennifer Lawrence rates pretty high up in the list. Even though she hates the idea of dieting, the star spends considerable amount of time doing cardiovascular exercises. She was named the second fittest celeb of the year.

Less than three months after delivering baby Luna, Penelope Cruz turned up on the red carpet looking like a million bucks. The magazine writes: "She credits following a Mediterranean diet, dancing, and chasing her kids for getting her back into shape after both pregnancies."

Now, if only we were that lucky!