Exercise in slow motion

As reported by Dr. Max Gomez, WNBC

New York, March 1 -- We all know that aerobic exercise such as walking, biking and running is good for cardiovascular health. What's been ignored in the fitness equation, though, is weight training. Now a dramatically different way to lift weights is gaining followers. You can get very strong by going very slow.

YOU KNOW THE DRILL -- grunting and groaning while you try to build some muscle for what seems like hours in the gym…when you go at all, that is. And then you get sore or hurt and may not get the results you want.

“I have never found anything that strengthens muscles without hurting joints,” said Lucy Perrotta.

And Perrotta's a doctor who knows how to train correctly. Then she found something that would make her stronger without hurting her joints, and it's very different from conventional strength training.

It goes by various names -- super slow or slow motion. What they all have in common is moving the weights very slowly. A ticking metronome helps set the leisurely pace although the feel is anything but.

“It's an extraordinary amount of work in a small amount of time and you have to really fatigue your muscles to really feel it,” Perrotta said.

The idea behind what makes a muscle bigger and stronger is to work it to exhaustion, to fatigue. With classic weight training, that means multiple sets of 10 or 12 repetitions each, at the end of which you've worked the muscle to exhaustion or fatigue and that's what triggers the biochemical and physiological changes that makes the muscle bigger and stronger.

What slow motion exercise says is why waste all those repetitions? Use much less weight, but do it so slowly that, surprisingly, you exhaust the muscles in just 60 to 90 seconds, but you still get to that point of exhaustion that triggers the bigger and stronger response. You just do it more safely and faster.

“The objective is to fatigue the muscle in a safe way so you're not going to hurt yourself,” said Dr. David Menche of the Hospital for Joint Diseases. “You definitely lift less weight and you can get to the fatigue without overloading the joint.”

Fred Hahn has been a proponent of slow motion exercise for several years now. He says that because slow motion is such an efficient muscle builder, you can workout much less frequently.

“We find that people who train once very fifth day or once every week experience tremendous increases in strength, endurance, and levels of health so that, essentially, what you're trying to do is find the least amount of exercise necessary to bring about the best gains,” Hahn said.

Kathleen Hayes is an anchor for our sister network, CNBC. She's been doing slow motion just once or twice a week, a half-hour at a time for about nine months. She has lost 25 pounds.

“My body has a tone. My muscles have a definition that they've never had before with anything else I've ever done. I'm stronger. I have more energy. I feel more confident,” Hayes said.

Weight loss, or fat loss actually, is the added bonus to strength training. Because muscle burns more calories than fat, even while it's just idling, slow motion exercise changed Bob Brusca's body.

“Five days a week, running 15 miles a day, I lost over a year and a half about five pounds,” Brusca said. “I came here, cut my workouts to twice a week, focused more on the diet -- a protein-based diet -- and lost 45 pounds in six months.”

Some zealous advocates say that slow motion is all you need to stay healthy, even to the point of saying that aerobic exercise is unnecessary. While slow motion clearly increases muscle strength, most experts say the jury is still out on its cardiovascular benefits. So lift and jog.