The actress and mom of three keeps her slim figure by hitting the gym with her husband Mark Wilkerson
Credit: Courtesy of Nutrisystem

Forget dinner and a movie. Working out is the perfect date, according to Melissa Joan Hart and husband Mark Wilkerson.

After losing a total of 40 lbs. over two years with Nutrisystem, Hart decided she’d like to try transforming the muscles in her body – with the help of her husband.

“Since he’s such an avid workout guy, I wanted to have him train me to see how my body could shift and change,” Hart, 38, tells PEOPLE.

But their gym sessions are also about carving out quality time as a couple.

“This is a good way to join together and spend time – just the two of us – away from the kids,” says Wilkerson, 37. “[It also helps] get her back in shape after three babies,” he adds, referring to their boys Mason, 8, Braydon, 6 and Tucker, 2.

As much as Hart enjoys it, she says she knows exercise is only 20 percent of maintaining her weight loss.

“You can’t out-train bad nutrition. I love that saying,” says the actress, who prefers not to rely on the scale but rather on how her jeans fit.

“Eighty percent of it is nutrition,” she adds. That’s why she sticks to Nutrisystem shakes for breakfast, salads for lunch, and either chicken and beef with vegetables for dinner.

The couple – who stopped by the PEOPLE Now studio to share some of their workout moves – spend one hour, three days a week focusing mainly on weight training. Hart also attends cardio classes two other days a week.

“I’m very much driven by working out with peers or working out with Mark,” says the 5’2” Melissa & Joey star. “If I’ve signed up for a class or I promised someone I’d be there, it just helps motivate me.”

For other couples looking to get fit in the new year, in addition to hitting the gym they can Pledge to Lose with Nutrisystem and enter for a chance to win three free months on the program.

“With kids and work it can be very challenging,” says Hart. “But if you can commit to just two hours a week to exercise together, it’ll work.”