It was at 01.00 that it started to burn in an apartment in Luleå.
The owners then called the rescue service but then managed to put out the fire on their own.
They also pulled out the power and dragged out the damaged treadmill on the balcony.
SOS Alarm tells SVT Norrbotten that no person was injured in the fire, even the apartment survived without smoke and fire damage.
It is unclear whether the treadmill was used or not when it started to burn.