Only four months after the "American Idol" victor became a mother for the first time, the country star has already recovered her usually slim figure, and her famous trainer's already two steps ahead of everyone by revealing Carrie Underwood's baby weight loss secrets.

Erin Oprea, who has been training the "Blown Away" singer for years, recently spoke to People Magazine about Carrie Underwood's baby weight loss, an astounding feat considering she only gave birth in February and she's already looking radiant - and it seems like a typical workout routine for Ms. Underwood has a lot of "warm up and a cool down" going on!

Oprea says that, to achieve Carrie Underwood's baby weight loss, the singer went through months of mixing it up in her workout routine, from running in a place with a lot of hills to then stopping at a park for push ups, step ups and the like, in an attempt to both keep it fun and not let the body get used to a routine.

The Inquisitr reports that the Grammy winner's taking Carrie Underwood's baby weight loss seriously as a business venture, and she's even releasing her own fitness wear line, Calia, which will be available both online and at Dick's Sporting Goods.

Celebrity Health & Fitness reports that Carrie Underwood's baby weight loss wasn't all about training, as the new mom of baby boy Isaiah also followed a vegan diet after the birth of her first child - as she's been a longtime follower of this kind of diet.

She's not the only top celebrity who has chosen to leave animal products out of her diet altogether, as megastar Beyoncé, Oscar winner Jared Leto and even Demi Moore have chosen to follow this same path due to its many benefits for the body, including anti-aging health benefits.

In any case, Carrie Underwood's baby weight loss is amazing - you can check out the results above!