Everyone wants to know Kate Hudson's secrets for staying in shape inside and out.

Except there is no secret, Hudson said recently in an interview on "Good Morning America."

"It takes a lot of work," she said, attributing her happiness to regular exercise, meditation and diet. "But it makes me happy; it makes me feel better."

The actress, fitness brand founder and now author is in town to promote her new book, "Pretty Happy: Healthy Ways to Love Your Body." The book covers topics like sex, motherhood, spirituality and even pole dancing. But it's not a beauty book, or a diet book, or even a fitness book, she said. It's a book about ambition and determination.

The 36-year-old says she's in the best shape of her life and hopes the book inspires women who struggle with motivation to overhaul their own lives.

Hudson is also the co-founder and face of Fabletics, the active wear company that last year brought in more than $150 million in revenue. Fabletics recently announced it will be opening a 2,000-square-foot store at the Mall of America later this spring.

Known for being an open book in Hollywood, Hudson remains mum on her speculated romance with pop star Nick Jonas. Jonas, 23, recently said he and Hudson have a "beautiful connection."

Her thoughts on that beautiful connection? "He's a great guy."

Hudson will be signing books at 2 p.m., Sunday, in the rotunda at the Mall of America.

Aimee Blanchette • 612-673-1715