CARL FOSTER, an exercise physiologist at the University of Wisconsin, La Crosse, was amused by ads for a popular piece of exercise equipment. Before-and-after photos showed pudgy men and women turned into athletes with ripped bodies of steel. And it all happened after just 12 weeks of exercising for 30 minutes three times a week. Then there was the popular book, with its own before-and-after photos, promoting a program that would totally change your body in six weeks with three 20-minute exercise sessions a week.
There are many examples of people who took up exercise and markedly changed their appearance. But how long does it take? And how much time and effort are required? Six weeks sounded crazy to Dr. Foster.