From blogTO:
Old Sweats Lane is marked on most maps as Industrial Parkway N., but that’s no fun. Hidden in the northeast corner of the city near Kingston Road and Ellesmere, the short stretch of road provides access to a branch of The Royal Canadian Legion.
According to Les Goodman from the Branch 258, “old sweats” is a common nickname for soldiers with lengthy service records, particularly those that served in the world wars or Korean War. The legion, one of the few in old Metro with a step-free entrance, used to put on a popular old sweats dinner that inspired the name of the lane.