"Working out allows me to spend time on myself," the 43-year-old actress told Shape magazine. "Knowing that I have an hour to dedicate to my wellness is a priority for me now."
Some of Mendes' favorite exercises include intervals workouts like running, sprinting and lifting weights, she said. But, she's currently working around a herniated disc in her lower back, which has disrupted her typical workout routine.
"I love squats, but I've been told that I have to do lunges instead of squats for the time being. I know a lot of people wouldn't find that heartbreaking, but I really do," she said.
Mendes said she works out three days a week during the "off-season," and never more than five when it's summer or she's preparing for an event. She avoids working out every single day, she said.
"I see better results when my body has a rest period," she said.
She also credits her daughters, 2-year-old Esmeralda and 11-month-old Amada, with helping her stay in shape.
"In some ways, it's been more challenging to get back in shape after my second daughter. Yet it's not as hard as I thought it would be, because I'm always running around with the kids," she said. "I never sit down -- I'm on the move all day. And I don't keep junk food at home anymore, because I'm trying to set a good example."
She told the magazine that she hasn't given up on all her unhealthy snacks, though. She still orders food delivery and indulges in Cadbury eggs like the rest of us.
"The mini ones and the big ones with the filling," she said.
Mendes enjoys time at home with her daughters, even while Gosling has recently been away on the awards circuit for his Oscar-nominated performance in "La La Land."
"What people don't know about me is that I love being home," she said. "Instead of hitting the red carpet, I'd rather be with our girls."