Lifestyle Health Katie Holmes Describes Her Favorite New Workout: 'It Puts Me in a Much Calmer Place' Katie Holmes talks about getting fit for her latest role — as well as being inspired by her daughter Suri — in the April issue of Women's Health By Stephanie Petit Stephanie Petit Stephanie Petit is a Royals Writer and Reporter at PEOPLE. People Editorial Guidelines Published on March 7, 2018 09:00 AM Share Tweet Pin Email Thanks to a new movie role, Katie Holmes is in her best shape ever. The 39-year-old actress covers the April issue of Women’s Health, where she talks about amping up her workout routine for the upcoming action-thriller The Doorman. To get the look of an ex-Marine, Holmes’ gym time consisted of lifting weights and personal training sessions that sometimes lasted two hours. “I wanted to be authentic to a person who trained in the military,” she said. “Which means someone who wasn’t always paying attention to the mirror and who was in shape not for vanity, but because that’s what her job called for.” Ben Wats But her intense training had offscreen benefits as well, including stronger muscles and a newfound love of boxing. “I was a five-pound weight person, and now I can do 15, 20,” Holmes shared. “And I’ve been doing a lot of boxing, which I had never done before. It’s thrilling. You can get out the stress of the day. I just go in there and think of all the mundane things that bother me. Traffic! I put off all my calls till after boxing, because it puts me in a much calmer place.” Ben Wats Ben Wats Holmes also gets real about staying fit — with her 11-year-old daughter Suri in mind. “Being a parent, every choice I make it with my child in mind. So part of getting in shape is to be an example,” she told the magazine. RELATED VIDEO: Katie Holmes Quietly Supports Long-Rumored Partner Jamie Foxx at Store Opening The Dawson’s Creek alum sticks to mainly plant-based foods but makes an exception for the occasional slice of pepperoni pizza. “It used to be about fitting into my jeans, and I’m so sick of that,” she said of her eating habits. “Now I think of it more as a health decision.” Ben Wats Holmes also likes group workout classes like SoulCycle, sharing that she enjoys the “sense of community.” She explained, “Like, if she can do it, I can do it too.”