At the height of his career, Cyr stood only 5'10" tall but he weighed over 300 pounds and had a 60" chest when it was expanded (55.2" normally). Several of his weightlifting feats and strongman stunts have been exaggerated over the years but some were documented and are still considered impressive today. Examples: he back-lifted a platform holding eighteen men; he lifted 553 pounds off the floor with one finger; he pushed a freight car up an incline.

One of Cyr's most-talked about stunts occured on 10 December 1891 in Montreal. Four horses were tied to his arms (two on each side) and, while the grooms whipped and urged the horses to pull, Cyr managed to restrain all of them.

Louis Cyr died in 1912 and many say he ate himself to death. The official cause, however, was listed as chronic nephritis.