Image source: Planet Fitness.

Looking buff, Planet Fitness (NYSE:PLNT). Shares of the company behind the fast-growing chain of budget-priced gyms hit all-time highs on Aug. 12 after posting another period of blowout financial results.

Revenue for the gym operator's second quarter clocked in at $91.5million, 16% ahead of the prior year's showing. Another period of double-digit percentage growth was the handiwork of franchisees opening more stores -- 36 during the second quarter alone to hit 1,206 total locations -- and a 7.6% spike in same-store sales. 

Gyms may seem like finicky operations, but the growing popularity at Planet Fitness has been remarkably consistent. It has now rattled off 38 consecutive quarters of positive comps. That's a lot of pull-ups in a row!

The model is as scalable as you probably think. High-margin franchisee revenue trickles down the income statement, and every subsequent addition to its empire improves its cost efficiencies. If the 16% year-over-year uptick in revenue isn't impressive, the 19% pop in adjusted EBITDA and 28% surge in adjusted net income should scratch that itch.

Planet Fitness' profit of $0.17 a share blasted through the $0.15 a share that analysts were targeting, but that isn't much of a surprise. It has beaten Wall Street earnings forecasts by a double-digit percentage margin in every quarter during its brief tenure as a public company.

The fall and rise of a gym operator

Planet Fitness wasn't a hit out of the IPO gate last year. It went public at $16 last summer, but bottomed out as a busted IPO in February at $13.23. Like a good gym workout, Planet Fitness has gotten itself back in shape after a series of impressive reps. You don't consistently beat expectations and push guidance higher without being rewarded. 

The model is resonating with folks that don't typically frequent pricier gyms. The value proposition at Planet Fitness is clear. Folks pay as little as $10 a month. Planet Fitness may not offer organized group fitness classes, day care centers, swimming pools, and racquetball courts, but access to a huge arsenal of treadmills, elliptical machines, and other workout gear for the cost of a streaming video service works. 

The Planet Fitness revolution will continue to gain steam. It is looking for franchisees to open between 210 and 220 new stores this year. It sees adjusted earnings of $0.63 a share to $0.66 a share on $366 million to $372 million in revenue for all of 2016. The low end of its top- and bottom-line ranges were the high end when it initiated guidance earlier this year.

Planet Fitness keeps appealing to the 80% of the country that doesn't currently have a gym membership. The math makes sense, and now the stock does, too. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.