Is Cardio-Free the Way To Be?

April 13, 2007 — -- "Cardio kills," says Jim Karas in his new book, "The Cardio-Free Diet."

"Cardiovascular exercise kills a weight-loss plan, your internal organs, your immune system, your time and your motivation. If your true goal is to lose weight, interval strength training is the only way to go," says Karas, an ABC News correspondent, celebrity trainer and fitness expert.

When he first tried to lose weight as a 21-year-old, Karas found that he would work up an enormous appetite after running several miles. So while his cardiovascular health improved he still wasn't losing weight.

He grew more interested in strength training and started exercising with weights. In a short period of time he noticed changes in his body's composition. Gradually, experimenting on himself, he started doing more strength exercise and less cardio -- and his weight went down.

His experiment resulted in a cardio-free exercise program that includes two routines with 10 exercises. Every two weeks, after beginning with Phase 1, you add two exercises as you progress to the next phase, ultimately getting to Phase 4.

Most of the exercises require you to use many muscles at the same time, increasing the number of calories burned and maximizing the creation of new muscle tissue.

According to Karas, with his program you still get all three elements -- strength training, cardio and flexibility. He says people who engage in his program see an increase in their heart rate.

"It's really a three-for-one solution, when you look at exercise," says Karas.

Exercise physiologist Richard Weil is not convinced. "I'm flabbergasted, I'm astonished at what I'm reading. I genuinely believe he's deluding people and he's leading them to believe information that is really not factual. I believe that the book is dangerous."

Weil, director of the weight-loss program at the New York Obesity Research Center at St. Luke's-Roosevelt Hospital Center, says it's untrue to suggest that aerobic exercise is not effective or helpful.