Les Mills was founded in 1968 by Olympian and Commonwealth Games gold medallist Les Mills and his wife Colleen.

Today the exercise company has 12 national gyms and is still growing, aiming to have 75,000 members throughout New Zealand within five years. Les Mills is currently completing a $35 million makeover of the flagship gym Les Mills Auckland City to be completed in 2020.

Its sister company, Les Mills International, is focusing on fitness programmes which are used in 19,500 gyms in 100 countries.

ExerciseNZ chief executive Richard Beddie says Les Mills has been a leader in the New Zealand industry for six decades.

“Through their chain of national clubs, one of the largest in New Zealand, and their group exercise programmes which is licensed to more than 80 clubs in the country, Les Mills continues to be one of the most significant and influential organisations in our industry. 

“They have driven quality an innovation in group exercise, as well as customer experience, and have helped shape the industry into what it is today.  

“Celebrating 50 years in any industry is a milestone, but particularly so in one so young as ours,” Beddie says.

Les Mills head of research Bryce Hastings, who is based in Chicago, works with leading academic institutions such as Penn State University to ensure all Les Mills classes are independently tested and this data is used to produced peer reviewed studies published in academic journals.

One of their studies was undertaken recommended an upper limit of high intensity interval training at 30 to 40 minutes working out at above 90 per cent of the maximum heart rate each week. 

High intensity training typically involves periods of extreme exertion where people push their heart rates to greater than 85 percent of their maximum capacity followed by periods of rest.