The Gym Group said it continued to trade strongly with membership increasing by nearly a fifth year on year to over 500,000.
An update ahead of its capital markets day for institutional investors and analysts said that trading for the first five months of the year had met the board's expectations and profit for the full year was anticipated to be in line with consensus market forecasts.
It said that six new gyms would have opened by the end of the first half increasing the total estate to 95 sites.
It said two of the sites at Holborn Circus and Bloomsbury were acquired from Fitness First UK in August 2016 and were subject to a full strip out and refurbishment to the Gym Group specification.
The other sites opened were at Edinburgh Murrayfield, High Wycombe, Altrincham and Rotherham.
It said all sites opened in 2017 were trading as expected.
Chief executive John Treharne said: "The group continues to trade strongly with membership increasing by nearly a fifth year on year to over 500,000.
"Six new gyms will have opened in the first half of the year and we are on track to meet our guidance which is towards the top end of our 15-20 range.
"There remains a substantial opportunity with strong fundamentals underpinning our growth and we are confident in delivering continued profitable progress."
At 8:01am: (LON:GYM) The Gym Group Plc share price was +5.38p at 199.38p