As the fitness industry moved into the new century, it experienced tremendous growth in club numbers, both in the United States and overseas. It also experienced growth in memberships, going over the 40 million mark for the first time. Much of that growth was from seniors and youth. Other issues, such as competition and tension between for-profits and nonprofits, clubs jumping into the public market, and a widening obesity crisis, also impacted the industry.

The first decade of the 21st century saw the emergence of Bahram Akradi's Life Time Fitness, which shared the spotlight with the more established 24 Hour Fitness and Bally Total Fitness. However, these three operations faced competition from other clubs of prominence during this time, such as Club One, Equinox, Gold's Gym, Planet Fitness, Town Sports International and World Gym.

For background about how many of these clubs made their mark in the 2000s and how they changed the industry, read the fourth article in the series of stories celebrating the magazine's 25th anniversary by going to www.fitnessbusinesspro.com/25th-anniversary.

For more details about some of the biggest club companies in the industry in the 2000s and how the industry experienced tremendous growth in club numbers, both in the United States and overseas, read the full story in a few days.