How Carrie Underwood Got Her Body Back After Baby

— -- Carrie Underwood just welcomed her baby boy Isaiah in March, but she already looks like she did prior to announcing she and husband Michael Fisher were expecting!

In this month's Shape magazine, Underwood, 32, explains how she lost the baby weight so fast, after only gaining 30 pounds during the pregnancy.

“After I had Isaiah, my goal was to take control of my body again. I was lucky: I gained only 30 pounds, which is the recommended amount, and I exercised throughout my pregnancy," she told the magazine. "I did have a C-section, which meant waiting six weeks before working out. Within 20 days, though, I was able to begin walking slowly on the treadmill and around my neighborhood."

She continued, "It felt so good to be active! Now we box and we hike trails, among other things. I like to continually mix up my routines to stay motivated.”

The "Blown Away" singer also dished on her favorite workout, Tabata.

"I can do [it] at home in about a half hour. I’m in love with it! It’s hard, but it really works," she said. "I choose seven different exercises, like squats, lunges, or push-ups, and do eight rounds of each – 20 seconds on, 20 seconds off for eight rounds. It really revs up my metabolism. When I’m done, I can handle anything.”

Her diet also changed drastically.

"I’m vegan and I love bread, but recently, I started making dinner a breadless meal. I’ll have a bowl of oatmeal for breakfast, and I’ll make a sandwich on Ezekiel bread for lunch, but in the evening I’ll have protein and vegetables and no bread. When I wake up, my belly is flat!” she explained.