BOSTON — When the International Health, Racquet and Sportsclub Association (IHRSA) researched the latest industry statistics that it released last month, the for-profit health club organization let its fingers do the walking.

IHRSA says the number of health clubs it released is based on the number of clubs listed in the Yellow Pages under SIC codes 799101 and 799102, subcategories of SIC code 7991. With the assistance of the codes, IHRSA estimated that the number of health clubs decreased by less than 1 percent from 30,022 in 2008 to 29,750 in 2009.

Earlier this year, according to IHRSA's research, there were about 29,200 clubs listed in the Yellow Pages. IHRSA took into account that several clubs have stopped advertising in the Yellow Pages and also factored in that although there were club closings and consolidation in 2008, there also were acquisitions in which struggling facilities were purchased by other club companies or chains.

“Given these two assumptions along with the number of clubs listed in the Yellow Pages, we estimate a total number of 29,750 U.S. facilities,” IHRSA says.

Using the SIC codes may not have been the most accurate way of gauging the number of clubs in the industry, says Michael Scott Scudder, who operates the fitness business education website CMETO.com. Scudder says SIC codes are not frequently updated, and in the case of SIC code 7991, several clubs listed may no longer be in business, which IHRSA did take into account. Also, the code usually does not include clubs that opened in the past six months, he says.

“SIC codes can be out of date by as much as 11 months,” Scudder says. “When was the SIC coding done? How relevant is it?”

According to Scudder's research, which includes the SIC 7991 code and results from various websites, the present club count is about 28,700, more than 1,000 clubs fewer than the IHRSA count.

Scudder also questions the number of members IHRSA calculated in its survey. In 2009, according to IHRSA, the industry had 45.3 million members, down slightly from the 45.5 million members in 2008. The decrease is “statistically insignificant,” IHRSA says, because the survey margin of error is 4 percent. Compared to previous years, membership has remained statistically the same since 2004, IHRSA adds.

“Can we say there's real accuracy in those numbers?” says Scudder, who adds that his research suggests about 43 million members in the United States. “How do they determine the number of members? You can't call every facility in the country.”

Of the 45.3 million health club members, about 23 percent, or 10.4 million members, were new, according to IHRSA. In addition, 7.2 million consumers used a health club as nonmembers in 2009.

IHRSA also says that total industry revenues increased by 2 percent to $19.5 billion in 2009 compared to $19.1 billion in 2008. IHRSA annually compiles industry revenues, taking into account the total number of members, total club revenues, and average membership and non-dues fees. The increase in revenues was due to increases in health club usage and non-dues spending, according to IHRSA.