By Patti Ghezzi
Almost 40 years after Dr. Kenneth Cooper coined the term "aerobics," a concept that would later spawn a generation of spandex-clad cardio junkies, some trainers are steering their clients away from traditional cardio-intensive workouts and toward mostly strength moves.
The reasons: Many exercises that are good for the heart are hard on the joints. And cardio training without muscle conditioning leads to loss of muscle and bone density as well as fat, experts say.
Even Cooper now believes strength training is important. Some people -- those fighting aging and those with injuries -- benefit from more time on muscle conditioning than
cardiovascular exercise, he said in an interview from his Texas clinic.
He cites Hall of Fame quarterback Troy Aikman, a one-time cardio king who shifted to more intense weight training. Cooper does not believe cardio is a bad habit altogether. "If you go strictly muscular-skeletal conditioning, it's a major mistake," he said. "You'll wear out."
Jim Karas, author of "The Cardio-Free Diet," believes cardio workouts overstress the body and work against those trying to lose weight.
Karas, who helped Diane Sawyer get svelte, experienced a revelation in the '80s when he was an aerobics instructor. He saw shocking amounts of excess flesh, even on those who came to class religiously. Then he looked in the sparsely populated weight room. "Everyone was so lean!" he said in an interview from his Chicago studio. Karas changed his approach and found he and his clients could keep weight off more easily with strength training rather than aerobics.
For those who love cardio workouts, Karas recommends no more than 30 minutes at a time, because of potential joint damage and his belief that cardio stimulates the appetite.
He favors "compound exercises" that combine upper and lower body moves and get the heart pumping.
"My whole goal is I just want people to stop pounding their bodies," he said. "When people hear 'exercise,' I want them to think of strength training."
Meanwhile, Cooper, 76, suggests an ongoing shift to more strength work as you age. His advice is based on his experience. As he aged, he had endurance but he lacked strength. He started lifting weights. Some younger athletes need to shift away from cardio because of injuries, he said. "If your body starts breaking down, listen to it."