Jessica Simpson’s had a year of ups and downs. While her new swimwear line sold a record-breaking number of suits, she’s had her share of heartache, too.

She broke up with singer John Mayer after an eight-month relationship in May, but she isn’t sitting at home crying into her pillow.

Jessica talked to In Touch from the set of her new film, Major Movie Star – about a Hollywood princess who joins the military – in Shreveport, La. “I’m having a blast!” she says. “The Army will definitely pull the best out of you.” Here is an excerpt from that interview.

You look amazing. Have you been working out hard? I am absolutely stronger than I have ever been. I’ve never been in this shape in my life. I am definitely seeing muscles that I have never seen before. I was like, “Wow!” I didn’t know that was possible.

Us Weekly reported that you recently weighed your heaviest – 145 pounds. I have never been that weight. I don’t mink that’s a healthy weight for someone who is 5′4″.

There are moments when I’m not dieting and there are moments when I’m not working out, but I feel more confident than I ever have about myself and I’m feeling better in my skin than I ever felt. It’s good to get better with age.

What’s your diet like? I try to stick to my trainer Harley Pasternak’s 5-Factor diet. I’m definitely a believer in healthy carbs. Lots of brown rice, lots of chicken, red snapper. But if I have a sweet tooth, I love sugar-free Jell-O. I’m also a big Fuze drinker. It keeps my energy up.

Was boot camp intense? This is the hardest movie I have ever done. Lots of sweat and tears. We’re pretty much going through basic training, in full fatigues, running around outside.

Today we had to run through tires and climb up walls in 100-degree humidity. I have gone in swamps with alligators. I am having to use Epsom salts for my bruises every single day! [via]