24 Hour Fitness’ founder, Mark Mastrov, has returned as owner and executive chair to accelerate the company’s next phase of innovation and expansion. LongRange Capital and Mastrov have partnered to acquire 24 Hour Fitness and support the company’s executive leadership team, led by President and CEO Karl Sanft.
Mastrov, who founded 24 Hour Fitness, grew the company from one club to 420 with a reported 4.5 million members, before selling it in 2005. He then led the purchase of Crunch Fitness in 2009, expanding it from several locations to 550 owned and franchised clubs before it was sold in 2025.
Fueled by demand for health and wellness, 24 Hour Fitness has invested in a nationwide remodel of its clubs and new experiences for members to meet personal wellness goals. The company employs roughly 7,000 people, ranking among the top three in the country for company-owned fitness clubs.
“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.”
Over the past two years, 24 Hour Fitness has rolled out an extensive remodel program and introduced a premium suite of offerings. The company has also deepened its community roots through expanded partnerships with major sports organizations across the NBA, NFL, and NWSL, strengthening its position in the fitness industry.
“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, 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.”
The company plans to announce new initiatives, partnerships, and global expansion plans throughout 2026.
RBC Capital Markets LLC served as financial advisor, and Paul, Weiss, Rifkind, Wharton & Garrison LLP acted as legal counsel to the investor syndicate. Sidley Austin LLP and AJB Law Group, PC acted as legal counsel to Mark Mastrov and his affiliated investors. Piper Sandler & Co. served as financial advisor, and Ropes & Gray LLP acted as legal counsel to 24 Hour Fitness.
Image courtesy 24 Hour Fitness
