It's a fair presumption on the part of media people that the people found sweating it out at health clubs are a desirable demographic. People who take the time to stay in shape presumably have a lot of other things going for them as well, good jobs, nice homes and a taste for the better things.

Those are fair assumptions, it turns out.

A recent Arbitron study reveals that 61 percent of health club members have a household income of at least $100,000 annually, and 21 percent have household incomes greater than $200,000.

The survey found that 73 percent have a four-year college degree.

The survey was conducted at six health clubs around the country and spanned 1,302 members. It was commissioned by IdeaCast Network, which provide advertising on TV sets in health clubs. The clubs involved were Town Sports International in New York, Spectrum in Los Angeles and Lifetime Fitness in Chicago, Dallas, Atlanta and Minneapolis.

Among the other findings:

The largest demographic is in the 35-44 age bracket, at 29 percent, followed by 45-54s at 27 percent. The next-largest demo is 25-34s at 18 percent.

In terms of education, 88 percent of health club members have some college, with 37 percent having a degree. Some 9 percent have some post-graduate credits and 27 percent have a graduate school degree.

The majority of health club members--81 percent--are homeowners, and 69 percent own a home valued at $250,000-plus, with 12 percent owning homes valued at more than $1,000,000.

In terms of frequency, 36 percent of members go to their club five to seven times a week, and that's by far the largest share. The average visit is for 1 hour and 38 minutes.

Further, the study reports that 70 percent watch TV while working out.