In its aim to be a "judgment free zone," Planet Fitness has mostly succeeded -- why the fitness franchise continues to be one of the country's most successful in a difficult market, including $500 million in revenue in 2011, according to Inc Magazine.

Every once in a while, the gym's core beliefs are challenged, such as when a noticeably shredded woman was asked to cover up so as not to intimidate the other customers. According to its founder, body builders have attempted to sue them on numerous occasions on grounds of discrimination -- with little success.

Though world's strongest men candidates rarely enter Planet Fitness because of its lack of powerful equipment (and aforementioned taste in less serious individuals), in my experience with the gym I've seen numerous examples of men/women on the upper end of the weight lifting scale. Ironically, that could be what separates Planet Fitness from other average Joe gyms: it's still legitimate enough for a serious lifter looking to pay $10 per month instead of $40 (and over). Based on my eight month run selling used, commercial grade fitness equipment, the gym is also known for carrying the latest brands while prescribing to the neat and sleek layout favored by higher end franchises.

"We got rid of unnecessary perks and went hard with cardio equipment," former CEO and co-founder Michael Grondahl told Inc Magazine. " We also provide weights, but our gyms don't include any of the big, heavy equipment that bodybuilders use. Bodybuilders don't really have any reason to join our gym, which is fine. They spend three to four hours training and make people who aren't in top shape feel uncomfortable. Some guys have attempted to sue us, but I guess bodybuilders aren't classified as a group you can discriminate against."

In the company's most recent incident to make national news, however, its alleged transgressions had little to do with its core beliefs. A woman member wearing a head-scar related to her Muslim faith was asked to remove it before working out. While she claimed she notified the staff member of her religion, the staff member asserts that she did not -- and thus the request was strictly a policy decision. The woman will take the case to court, scheduled for August, according to the NY Daily News.

Planet Fitness' current CEO is Chris Rondeau.