Although the national obsession for group exercise has begun to level off, estimates claim 23 million Americans participate in aerobics in health clubs and exercise gyms .... This includes people enrolled in programs run from community facilities, YMCAs, and gyms, to dance studios in shopping malls .... This figure represents 10% of the US population who exercise occasionally, definitely a fraction of what it used to be 10 years ago when the craze was at its peak and America was waking up to the urgent ....