Kipchoge 1:59 Marathon Challenge - what factors make the difference?
Team Ineos discuss the factors that could prove to be the difference for Eliud Kipchoge as he attempts to run a marathon in under two hours in Vienna, Austria this Saturday.
It will be the Kenyan's second attempt at becoming the first person in history to run a marathon in one hour 59 minutes.
Watch live coverage of the 1:59 Challenge, Saturday 12 October, 07:00-09:30 BST on the BBC Red Button, BBC iPlayer, BBC Sport website & app.