BOSTON -- Health club membership in the United States increased by 3 percent last year from 42.7 million members (over the age of six) in 2006 to 44.1 million in 2007, according to early estimates from an annual tracking study by the International Health, Racquet & Sportsclub Association (IHRSA). In addition, industry revenues increased by 5 percent to $18.5 billion, the study shows. This growth in health club membership represents an increase of more than 115 percent in 10 years, while growth in total revenues represents an increase of 127 percent.

The data, which appears in IHRSA’s annual membership report, Profiles of Success 2007, indicates that clubs have also improved upon membership retention from 2005 to 2006 by three percentage points, increasing from 70 percent to 73 percent.

Simultaneously, participating IHRSA clubs raised total revenue per member by nearly 5.5 percent in 2006 to $741.80.

“As an industry, we aim to grow total membership year after year, and industry stability is in no small part dependent on customer satisfaction, membership retention, and increasing revenues per member,” says Joe Moore, president and CEO of IHRSA.

In April of last year, IHRSA reported that health club memberships for 2006 had increased by more than 3 percent from 41.3 million in 2005 to 42.7 million in 2006. This increase came after a two-year stall in membership numbers in 2004 and 2005.

The typical club surveyed for the 2007 report in regards to non-dues revenue reported generating nearly one-third (32.1 percent) of total revenues from internal profit centers in 2007.

“These profit centers provide evidence of the clubs’ ability to develop programs and services that meet consumers’ fitness and recreation needs,” says Katie Rollauer, IHRSA’s senior manager of research.

Additional results found that clubs’ steady improvements in revenue growth (5.4 percent over 2005) and membership growth (4.2 percent over 2005) contributed to an overall improvement in productivity and profitability. Specifically, the typical business responding to the survey reported a 6.6 percent increase in the revenue per square foot ($53.50), while club profitability for the entire sample improved by better than three percentage points to 11.3 percent (pre-tax earnings a percentage of revenues) in 2006.

“These observations reflect a club’s ability to control costs while generating overall growth,” says Rollauer.