Anne Rust hasn't changed her gym ID photo from a year ago, when she was more than 40 pounds heavier.

And she has no plans to.

It's what she calls "motivation."

"I hate this picture," Rust said, holding it up. "I look at it and I don't ever want to be that person."

She paused to look at the photo again.

"No," she added. "I'll never be that person again."

It didn't take long — about six months — for Rust to shed those 40 pounds.

But now she's realizing just how hard it is to keep them off, especially during the holidays — and after her first trip to New York City.

"Oh, I ate anything and everything," Rust said, laughing.

So her goal for 2006: to be her fittest ever by the time she turns 50 on Nov. 1.

And it's not impossible.

Up through October, Rust was working out six days a week, taking an aqua aerobics and ball-strengthening class at the Honolulu Club.

She incorporates cardio — treadmill, rowing machine or Stairmaster — and weights into her normal routine. She also experimented with Tahitian and hip-hop cardio dance classes, for variety.

Rust credits her drive to stay fit to an active childhood.

The second — and most tomboyish — of three girls, Rust grew up swimming at the beach and riding dirt bikes in Waipahu. (She and her dad built a dirt bike once out of spare parts from a junk yard.)

At 4, Rust started dancing hula. At Campbell High School, she was on the swim team.

But somewhere between raising two sons and starting her own company 10 years ago, Rust, who was always "too skinny," had lost her fitness ways.

"As my kids got older, I was less active," said Rust, who had averaged 130 pounds on her 6-foot frame. Running her own company — Pacific Connection Fertility Services, which specializes in egg-donor recruitment and screening — took up most of her time.

She gained weight, until "even some of those size 18s were too small."

Rust got motivated when her younger sister, Jennifer, called in October 2004 to say she had lost 20 pounds on the South Beach Diet.

"I realized I had to put myself first and schedule (workouts)," Rust said. "It had to be something for me."

That month, a friend asked Rust if she would come check out the Honolulu Club with her. Rust agreed to go. She was so impressed by the club she immediately joined.

Rust decided then that in two years — when she turned 50 — she would be back into shape. She enlisted a personal trainer, Barbara Alfano, and went to work.

At first it was humbling. She could barely do four crunches.

Alfano reassured her that this was normal, it would get easier the more she worked out.

Alfano asked Rust to review a list of aerobic classes and pick one that interested her. She chose a low-impact aerobics class, thinking it would be easier than the others.

Well, not at first.

"I was woefully out of condition, and I tried too hard to keep up with everyone," Rust said. "I was very disappointed."

Then she tried aqua aerobics.

"I thought I had found exercise nirvana," Rust said.

In six months, Rust saw dramatic results, dropping pounds and toning muscles. She dropped from a size 18 to a size 10.

The change didn't register until June, on a shopping trip to Costco.

Impressed at her ability to easily lift a bag of dog food into her car, she noticed the poundage.

Forty.

Exactly the amount she had lost.

There it was.

"I stood there and looked at it, a physical representation of the weight I had lost," Rust said. "I felt a lump in my throat and my eyes teared up. It freaked me out."

While her lifestyle and eating habits changed, the biggest change came emotionally.

Rust went from hating to try on clothes at department stores to buying strappy dresses that showed off her sculpted arms.

She sleeps better, found a new food craving — baby spinach — and even teaches aqua aerobics at the Honolulu Club.

Being overweight, she said, had really affected her outlook.

"I've got so much more energy now, I'm so much happier," Rust said. "I've always known and believed that how you look affects how you feel."

Reach Catherine E. Toth at ctoth@honoluluadvertiser.com.