24 Hour Fitness has announced that founder Mark Mastrov has returned to the company as owner and executive chair following an acquisition completed in partnership with LongRange Capital. The transaction positions Mastrov and LongRange Capital as new owners of the brand, supporting the existing executive leadership team led by President and CEO Karl Sanft.
Mastrov founded 24 Hour Fitness and grew the company from a single location into a national operator with hundreds of clubs and millions of members before selling the business in 2005. He later led the acquisition and expansion of Crunch Fitness, growing it to more than 550 owned and franchised locations prior to its sale in 2025. His return brings decades of industry experience back to the brand during what the company describes as a strong period of growth.
According to the announcement, 24 Hour Fitness has invested heavily in recent years in club remodels and new member experiences, responding to increased demand for health and wellness offerings. The company reports employing approximately 7,000 team members and supporting more than 113 million workouts annually, placing it among the largest company-owned fitness operators in the U.S.
“Mark founded and built 24 Hour Fitness into the powerhouse brand it is today, and the organization is inspired and energized by his return,” said Sanft. “With the business stronger than ever and our investments aligned with what members value most, this is the perfect time to welcome him back. Together with LongRange Capital, we’re ready to accelerate our growth story.”
The company has also introduced new premium offerings over the past two years, including Recovery24, and expanded partnerships with professional sports organizations across the NBA, NFL and NWSL. These initiatives are part of a broader strategy to strengthen member engagement and reinforce the brand’s position in the competitive fitness market.
“LongRange Capital was founded on the belief that through strategic support, patient capital, and a focus on delivering greater value for customers, companies can develop into exceptional businesses over the medium- and ultimately long-term,” said Bob Berlin, the founder and managing partner of LongRange Capital. “24 Hour Fitness has an iconic legacy and significant opportunity ahead, and we’re excited to partner with Mark, Karl and the exceptional team at 24 Hour Fitness during this next phase of growth.”
With Mastrov returning to a leadership role and LongRange Capital providing financial backing, 24 Hour Fitness stated it plans to continue expanding its wellness offerings and community initiatives, with additional announcements expected throughout 2026.
Financial advisory and legal services for the transaction were provided by RBC Capital Markets LLC, Piper Sandler & Co., Paul, Weiss, Rifkind, Wharton & Garrison LLP, Ropes & Gray LLP, Sidley Austin LLP, and AJB Law Group, PC.
