VANCOUVER, Wash. -- Gyms were once the domain of beefy guys, heavy barbells and chalky hands.

Then a small company called Nautilus came along in 1970 and introduced machines that offered a more-targeted approach to strength training.

The Nautilus machines revolutionized the idea of the workout. The machines became ubiquitous -- Ronald Reagan even used Nautilus equipment in the White House when he was rehabilitating from his gunshot wound.

Today, gyms everywhere carry a Nautilus or Nautilus-like machine. Yet, the machine's design has remained relatively the same since its debut.

But on Thursday, Nautilus is unveiling the first major change to its gym strength training line, the result of the company's largest investment in research and design.

"What we set out to do with Nautilus One was create that same kind of industry-changing event through a product that would get people excited about getting into fitness training again," said Gregg Hammann, chief executive officer and president of Nautilus Inc.

The smaller and more stylized line includes a number of changes. The most significant is the complete departure from the noisy weight plates, pins and pulley system usually seen in gym equipment.

Instead, users will spin a dial to select their resistance, which will set the weight internally in the machine. Hammann likens the technology to the combination to a safe.

The company says the elimination of the traditional system will reduce friction for users and nearly eliminate maintenance for gyms. Plus the modular design will ease production and shipping demands.

The new design has the capacity to accommodate a wider-range of users, appealing to the changing demographic of the gym crowd.

Health club memberships have grown in recent years, with more than half belonging to women, according to the International Health, Racquet and Sportsclub Association. And the age mix is changing too: baby boomers and beyond are now becoming focused on the benefits of exercise as they age.

The boomer focus on health may be a boon to the entire fitness equipment industry, said Rommel Dionisio, a senior equity analyst with Wedbush Morgan Securities.

Nautilus is banking on the boomer revolution. The company has been making a string of revamps, Nautilus One being its latest, as it rebuilds from near collapse in 2003.

Nautilus Inc. encompasses Bowflex, StairMaster, Schwinn Fitness and Pearl iZUMi, but for many years the vast majority of its sales were from the Bowflex home gym.

The Bowflex was the fastest selling home gym in America. At its peak in 2002, its sales totaled $585 million and made up more than 60 percent of the company's business.

But Bowflex knockoffs and expensive litigation sent the company into a tailspin. Nautilus' net income dropped from 97.9 million in 2002 to $34.4 million the next. Investors abandoned the stock and analysts declared it dead.

In exercise terms, Nautilus had hit the wall.

Then Hammann came to Nautilus in July 2003 after helping make strides at companies like Coca-Cola, Levi Strauss and Proctor & Gamble. He brought on an almost entirely new leadership team and opened a major research and development lab.

He says 98 percent of the company's product portfolio didn't exist three years ago.

"The company is back on a growth trajectory," he said. "We are just getting started frankly."

Sales have rebounded gradually and while the company has projected limited revenue growth in 2007, analysts are optimistic.

"This is going to be a big launch for them for 2007," said Steve Colbert, an analyst with Canaccord Adams in Boston. "It's been growing at a good rate."

The company consolidated multiple distribution centers that were causing some analysts concern with its supply issues. And it recently announced plan to acquired the assets of its largest contract manufacturer in China.

Sales of the Bowflex product line now account for about 44 percent of the company's business. And it has moved away from direct sales like Bowflex's late-night ads with a big push in major retail chains such as Sports Authority, Colbert said.

Nautilus's gym line accounts for 15 percent of its business, Hammann says. And while sales of commercial equipment have trended more toward cardiovascular over strength products, Nautilus says it is hoping to see that market grow. It aims capture the continued growth in gyms and sell its existing customers with its new approach as it begins shipping this spring.