24 Hour Fitness has named Tony Ueber has its new chief executive, replacing outgoing CEO Chris Roussos.

Ueber, a former president and CEO of Results Physiotherapy will take up the post with immediate effect, with Roussos stepping down and remaining as a special advisor to the US-based fitness operator, to ensure a "smooth and effective transition".

“After an extensive strategic review and development of our company’s new value proposition, the board came to the conclusion that the company required a different CEO skill set to achieve its transformational objectives,” said Roland Smith, chair of 24 Hour Fitness.

“With 25 years of demonstrated success across a diverse background of experiences in the consumer products, retail and healthcare services industries, Tony has the unique skill set and experience required to execute on the strategic plans we have laid out to transform 24 Hour Fitness into the clear industry leader.”

At Results Physiotherapy, Ueber was credited with leading the transformation and rapid growth of the company, which offers physiotherapy services at 140 locations across nine US states.

Over the past four years, Results Physiotherapy has more than doubled the number of locations and entered seven new markets.

“I am excited to join the 24 Hour Fitness team and fundamentally believe in the vision and mission of the business and the potential for the company to become the definitive leader in the industry,” Ueber said.

“I am confident that we can build upon the solid foundation that Chris has built to take the Company to new heights.”

The appointment was made public on the same day as the company launched a new strategic approach, designed to personalise its fitness offer.

"Americans understand the importance of fitness to their health and ability to achieve what they want in life, yet many still struggle to fit it into their daily lives or create lasting results," the company said in a statement. "So the time has come for a behaviour change solution.

"The key to the solution lies within a powerful combination of science, technology and 12,000 fitness professionals and group exercise instructors brought together to personalize fitness for everyone."

The new strategy will introduce a number of new measures, such as members having a free assessment by a fitness professional, resulting in a personalised, seven-day plan – featuring activities inside and outside of the gym – and the use of a 24GO mobile app to track members' progress.

Based in California, 24 Hour Fitness operates 430 clubs across the US and has more than 4 million members.