Obree was at his peak in the 1990s

Obree, who held the record before Boardman set his mark of 49.441km, said it became clear in tests that he was too far away from fitness.

Obree, 38, has been retired from top-level cycling since 2001.

"I was averaging 47 kmph, so I quickly realised that I was not ready and I stopped after 12 minutes," he said.

"Given that I can only train on the road (there is no velodrome in Scotland) it will take me far too long to get back to the level required. So I've decided to give up the idea of breaking the record and I will now have to reconsider my objectives," Obree added.

Obree won at the 1993 world track championships in Norway on a homemade bike with a bearing taken from an old washing machine.

In the same year, he broke the one-hour world record by covering 51.596 kilometres but the record stood for just six days before Olympic gold medallist Boardman shattered it, only for Obree to reclaim the record in 1994.

His new mark was subsequently beaten by Spain's Miguel Indurain, Switzerland's Tony Rominger (twice), then Boardman.

New rules were then introduced, limiting the extent to which bicycles could be adapted from standard models.