Rondeau, who had served as Planet Fitness CEO since 2013, will remain on the company's board. Craig Benson, a member of the company's board of directors, will serve as interim CEO until a permanent replacement is named, the company said, adding that the management changes were not tied to any "unexpected financial events."

It gave no reason for Rondeau's departure as CEO.

Planet Fitness shares dropped as low as $50.21, their lowest since March 2020, after Rondeau's departure was announced. The stock has so far lost about 34% year to date.

"While PLNT (Planet Fitness) saw significant growth during Rondeau's tenure as CEO, the transition announcement follows a more recent period of stock underperformance driven primarily by lower-than-expected franchise store growth," said RBC analysts led by Christopher Carril, in an investor note.

The analysts have an "outperform" rating on the company's shares.

Planet Fitness owns as well as operates as a franchiser of fitness centers across the U.S., Canada, Mexico and Australia, with about 2,500 locations. In August, the company reported that its revenue rose by nearly 28% to $286.5 million in the second quarter while net income nearly doubled to $44.2 million.

The median price target from 18 analysts covering the stock is $78, with most of them assigning a "buy" or "strong buy" recommendation, according to LSEG data.

"Despite this leadership adjustment, we wouldn't expect any change in the company's strategy near team," said Jefferies analysts led by Randal Konik in an investor note.

(Reporting by Chibuike Oguh in New York; Additional reporting by Chuck Mikolajczak; Editing by David Holmes)

By Chibuike Oguh