A return no one predicted
In January 2026, a news item slipped through the year-opening noise without getting the attention it deserves — at least for anyone following the gym industry. Mark Mastrov, the founder of 24 Hour Fitness, reacquired the chain he built and sold 21 years ago, this time with private equity firm LongRange Capital alongside him.
This isn't a nostalgia story. It's a precise investment thesis in a market consolidating at high speed.
The context: a chain that nearly disappeared
To understand the strategic logic of this acquisition, you need to trace 24 Hour Fitness's trajectory since 2005. When Mastrov sold the chain, it had roughly 420 clubs and 4.5 million members, valued at over $1.6 billion. A genuine fitness industry success story.
Then COVID hit. In 2020, 24 Hour Fitness filed for bankruptcy under the weight of its leases and forced club closures. The chain emerged from bankruptcy with roughly 240 clubs, concentrated mainly in the western US. The brand was still standing, but weakened.
That undervalued asset is what Mastrov and LongRange saw as an opportunity.
Mastrov's profile: one of the sector's most credible operators
To assess the credibility of this acquisition, look at what Mastrov did after leaving 24 Hour Fitness in 2005. In 2009, he acquired Crunch Fitness — a small New York-based chain present in a handful of cities. When he sold Crunch in 2025, the chain had 550 locations — growth of more than 100x in 16 years.
That's one of the most impressive growth trajectories in the US fitness industry. That track record transforms the 24 Hour Fitness reacquisition into something different from a standard LBO: it's an operator who knows this business intimately, who understands what drives growth in this sector, and who's returning to a brand he built from its foundations.
The announced strategy: renovations and new openings
Mastrov comes back as Executive Chair, alongside existing CEO Karl Sanft who stays on. The role division is classic for this type of acquisition: the veteran operator brings strategic vision and industry relationships; the operational CEO manages day-to-day execution.
The announced plan: use LongRange capital to complete renovations of existing clubs — many 24 Hour Fitness locations are aging and haven't seen major investment during the difficult years — and open new locations. The goal is to put the chain back on a stable growth trajectory in the western US, where it's still well-established and recognized.
What this says about the US fitness market in 2026
This acquisition fits into a broader trend the fitness industry has been watching for 18 months: a wave of consolidation and restructuring touching chains of all sizes. Workout Anytime announced a strategy of acquiring independent clubs to convert them to its brand. Crunch (now sold) is expanding through new franchisees. Planet Fitness continues its methodical growth.
In that context, Mastrov's return to 24 Hour Fitness represents a different approach: not organic franchise expansion, but direct takeover of an established brand with unrealized potential. It's a bet that distressed or undervalued fitness assets can be turned around by operators who know the sector intimately.
Questions the industry is watching
A few questions remain open. 24 Hour Fitness's geographic concentration in the western US is both an asset (established brand, real estate already in place) and a constraint (limited national growth capacity without further acquisitions or a hybrid format). The economics of large-format general gyms also face structural pressure from the rise of boutique studios and digital solutions.
Mastrov knows these challenges better than anyone. The question is whether he has a new answer — or whether he's relying on the same playbook that worked at Crunch in the 2010s but faces a different context in 2026.