The opening date have been given as November.
A new 24-hour gym is set to open in Offaly later this year.
Planning permission for the development of the Snap Fitness facility in the Tullamore Retail Park was granted in April.
It will be based in the former Carpet Right premises, which had remained vacant for almost a year.
The gym will include cardio and strength equipment, large-screen treadmills and 10,000 sq ft of workout space, and is set to open in November.
It will be Snap Fitness’ sixth location in Ireland, with sites already in Sligo, Drogheda, Galway, Navan and Waterford.