A man in his 40s was seriously injured in a fight outside Planet Fitness gym in North York early Monday.

Sgt. Rick Rowsome, of Toronto Police Service's 31 Division, said the man was hit in the head with a piece of wood on York Gate Boulevard, near Jane Street and Finch Avenue West. 

The man was taken to a trauma centre with non-life-threatening injuries. 

Jennifer Chung, deputy commander for Toronto Paramedic Services, said paramedics received a call about the assault shortly before 1 a.m.

Rowsome said police do not know what led to the assault. No arrests have been made and officers are reviewing surveillance camera video.

No suspect information was released.