Elsa Pataky and Chris Hemsworth's relationship requires "constant work"

Elsa - who has India, eight, and six-year-old twins Sasha and Tristan with the actor - shared: "It's funny that people think of us as a perfect couple. No way.

"It's been ups and downs, and we still keep working at the relationship. I think a relationship is constant work. It's not easy."

Despite this, Elsa always retains a positive attitude towards their relationship, and revealed they've bonded over their love of the outdoors.

Speaking to Body+Soul magazine, the model explained: "[Chris and I] love to do sports, eat healthy and move our bodies."

Elsa is determined to stay in good shape because she feels "strong" when she's exercising.

In fact, the blonde beauty revealed she still wants to be able to ride horses when she's 80 years old.

She shared: "If I'm not exercising, I don't feel strong. I feel soft and I don't like it.

"I am a very active person. I want my body to stay young - in strength and energy. I want to still go horseriding with my daughter when I'm 80!"

The celebrity couple - who live in Byron Bay in Australia - have managed to encourage their kids to embrace the outdoors, too.

Elsa said: "We've got the kids into surfing.

"Any hobbies to get them outside, and not on social media and computers. My daughter has been horseriding with me since she was two-and-a-half."

However, Elsa was forced to slow down during her pregnancies, and she can still recall feeling "a bit lost" at the time.

She said: "I had to slow down during my pregnancies and I couldn't exercise as hard as I wanted.

"I remember feeling a bit lost when I had India. I thought my life was going to be the same [when I had kids] and I would keep working. But I couldn't."