Kate Beckinsale Spills on Why She Can't Quit Her ''Incredibly Punishing" Fitness and Diet Regimen

Actress appears on the cover of Shape magazine

By McKenna Aiello Dec 28, 2016 1:20 AMTags

Kate Beckinsale works hard for her bod. 

The 43-year-old actress appears on the cover of Shape magazine's January/February 2017 issue, looking more toned than ever in a barely-there, colorblock bikini.

As for how Kate prepped for her physically-demanding role in Underworld: Blood Wars, she attributes those rock solid abs to celeb fitness guru Gunnar Peterson for pushing her to the limit.

"I work out hard with Gunnar five or six times a week," Beckinsale revealed, adding, "I do circuit training interspersed with brutal cardio, such as crazy things on a nonmotorized treadmill. That part is torture. But the thing I like about circuit training is that you're never doing one thing for very long. You get to the point where you almost can't bear it, and it changes to something else."

Kate wasn't always such a dedicated fitness freak, but that all changed when she recognized the benefits working out had on her mental health.

Celebrity Fitness Stars

"I start out absolutely dreading it, do an incredibly punishing workout, bitch about it the whole time, and end up feeling 100 percent better when I leave. Working out is basically nature's antidepressant," Beckinsale added. 

The brunette beauty explained that although she loves practicing yoga, "Hard-core workouts have really made a big difference in my life. I have a lot of internal energy, and intense exercise helps me channel that energy. I find balance by doing a workout that makes me pour sweat. I never was that girl before, but I am now."

As for Kate's nutrition plan, let's just say cheat days are few and far between. 

A longtime vegetarian, Beckinsale began introducing meat into her diet for extra energy while filming Pearl Harbor. She explained, "[My 17-year-old daughter] Lily and I eat clean—we have a lot of sautéed vegetables like brussels sprouts and broccoli and chicken and fish."

"Also, I don't drink alcohol," she continued. "I feel [its effects] very quickly, so I've never actually had an entire glass of anything alcoholic."

For more from Kate, pick up the latest issue of Shape when it hits newsstands Jan. 3.