Mark Smith has left his post as chief executive officer of 24 Hour Fitness and been replaced by Frank Napolitano, who has taken over the role in an acting capacity.

The operator's board of directors and Smith mutually agreed that he would step down from his role.

Smith became chief executive in July 2014, shortly after Forstmann Little sold the gym chain to a group of North American investors for US$1.9bn (€1.4bn, £1.3bn).

Napolitano, who is also president of 24 Hour Fitness, said: “We are thankful for Mark’s contribution to the company over the past two and a half years.

“During Mark’s tenure, the company maintained a strong and consistent level of revenue and EBITDA. I look forward to working with the rest of the executive management team to keep driving results in the business and to grow our company.”

Last week, the operator signed a deal with the United States Olympic Committee, to become the official fitness partner of Team USA in the run up to Tokyo 2020.

Headquartered in California, 24 Hour Fitness serves nearly 4 million members in more than 425 clubs across the US.