He was a multi-time Amateur Athletic Association of England champion and won two gold medals at the 1908 Summer Olympics in London.

[4][5] He wanted to retire as he found training conflicted with his job, but was instead granted an extended leave period by the Police Force.

After returning, he was disqualified in his first race in April 1908 at the AAA event in walking over seven miles, but the following July, he won the two-mile title.

[2][5] He competed for Great Britain in the 1908 Summer Games in the 3500 metre walk on 14 July 1908, winning the race ahead of fellow Briton Ernest Webb, who took silver, and New Zealander Harry Kerr.

[14] Larner's name has been carried on the front of a Scania Omnidekka bus in the fleet of Brighton & Hove since October 2007.