Carrie Underwoodis opening up about why it’s crucial for her to have structure in her health routine.

The 36-year-old singer covers the April issue ofWomen’s Health, where she talks about maintaining her health regimen and practicing her own version of self-care.

After years of experimenting with counting calories and macros, Underwood said she has figured out the ratio that works best for her: 45 percent carbs, 30 percent fat and 25 percent protein.

Peggy Sirota for Women’s Health Magazine

Carrie Underwood

“I love rules,” she told the magazine, referring to tracking her nutrition. “This is how I feel good about myself, and this is how I operate.”

However, the “Blown Away” artist admitted to struggling with counting calories, reading labels and overexercising when first on tour after winningAmerican Idolin 2005.

“I would ‘fall off the wagon,’ then feel terrible and repeat the cycle,” she explained, adding that she would sometimes eat as few as 800 calories a day. “Your body is screaming ‘I need more calories. I need more carbs!’ ”

Now, the mom of two maintains a healthy diet — but still occasionally indulges in her “vice” of red wine while watchingThe Bachelor —and hits the gym to practice self-care.

Carrie Underwood

“If I can work out seven days a week — which doesn’t happen, but if I can — I’m going to. Because the next week, I might get two days,” she said, explaining why she tries to squeeze in a sweat session whenever possible.

Underwood also stressed the importance of planning ahead before going to the gym.

“When I walk in and don’t have a plan, I usually walk out,” she told the outlet.

“It’s been more about health, and being strong, and setting a good example for my kids, and working out because it makes me feel good,” Underwood, who shares sonsIsaiah Michael, 5, andJacob Bryan, 13 months, withhusband Mike Fisher, said. “And just kind of shifting my mindset about why I’m into health and fitness.”

And as for her toned figure, Underwood works hard but doesn’t deny that genetics play a factor (especially when it comes to herfamous leg muscles!)“I think just in life and my body makeup, I’m just kind of a quad-dominant person,” she said.

The April issue ofWomen’s Healthhits stands March 17.

source: people.com