Four fire engines and around 25 firefighters were called to a fire at a gym on High Road in Ilford.
An air conditioning unit, a weight bench and around 3 metres of gym matting on the second floor of the building were destroyed by fire. There were no reports of any injuries.
The Brigade was called at 2123 and the fire was under control by 2255. Fire crews from Ilford and Barking fire stations attended the scene.
The cause of the fire is under investigation.