Even with a pair of gloves on to soften the punch, Miki Lee doesn't want to hit anyone. It just isn't her style.

But put her in front of a heavy bag in her kickboxing class and you'll witness a beating. Each thumping blow is Lee's deliverance.

She pummeled boredom and lost two dress sizes in the process. She lost weight — not much, maybe five to eight pounds — but is happier about having gained muscles. And she sleeps better, too.

At 46, Lee insists she is in the best shape of her life.

"I am strong and confident," she said. "I walk differently. I hold myself differently. I am probably taller."

A Honolulu business consultant, Lee had grown tired of aerobics, Pilates and yoga. She turned to kickboxing classes with martial arts expert Egan Inoue in December 2007 and discovered the joy of hitting. His classes at The Studio in Manoa were fast and furious and his students aggressive.

"The first class was bizarre, putting on gloves and running around the room and punching the bag," she said. "I was a sweaty mess by the end of it, and I was totally hooked."

The Studio has heavy bags hanging from the ceiling, but students sometimes also take shots at teachers wearing huge, padded mitts.

It's kickboxing with an important difference, Lee said.

"They are not hitting you back," she said. "They stay there and you hit them."

The 45-minute class also includes a variety of pushups, squats and stomach exercises that work her core muscles. The routine changes from session to session.

"It's highly effective," Lee said. "Some days there is no part of your body that hasn't been worked on. It's tough."

She struggled in the beginning. She was so weak, she could only do a pushup if she propped herself on her knees.

"I thought I was in shape, but I wasn't that strong," she said. "It became a challenge."

Now she can do 15 full body pushups and more situps than she counts, and she jumps rope.

"My body has changed," she said. "I am as limber as I was when I was in my 20s. I didn't think that would be part of it."

There was one other change Lee did not anticipate: her diet.

"I actually had to train myself to eat more to keep up with the calorie burn," she said. "There was a while there when I was leaving a jar of peanut butter out and whenever I walked by, I took a spoonful of it."

Because the classes change all the time, Lee remains motivated.

"You just can't get bored," she said. "There is always the mental challenge of doing it a little more or taking it to the next level. And as long as my body is responding, I should totally max it out in terms of pushing, taking it as far as I can to keep in this kind of shape."