NEWINGTON, NH -- Planet Fitness is discontinuing personal training at its clubs, according to CEO Mike Grondahl.

In a letter written to Planet Fitness owners, Grondahl says the Newington, NH-based company’s corporate-owned clubs will end all personal training sessions by Dec. 16. Franchisees will have until the first quarter of 2011 to end their personal training sessions.

“The decision to end personal training has been long and arduous,” Grondahl wrote in the letter. “It goes right to the essence of our business model. We’ve always tried to keep personal training to a minimum at Planet Fitness. But the problems related to having trainers in our gyms have never completely gone away. Lately, they’ve gotten worse. Too many trainers are pushing PT on our members, the vast majority of whom have zero interest in it. These clubs are opening themselves up to trouble.”

Grondahl says the clubs will continue their “P.E. at P.F.”—physical education at Planet Fitness—group fitness training sessions.

Grondahl began the letter by claiming that most people doing personal training are “just renting friends.”

“For us to be selling personal training is a fraud and downright condescending to anyone who can breathe,” he wrote.

Grondahl adds in the letter that personal training did not fit Planet Fitness’ “judgment-free zone” and that the company plans to use its no personal training model as a marketing tool.

“We’ll be the only fitness chain that can say we’ll never try to sell you personal training,” Grondahl wrote. “A lot of people will say we are dead wrong with this historic move. But the world was flat once, and who the hell needs a friend for 50 bucks an hour?”