Three elite runners backed by a small army of scientists will on Saturday attempt an audacious assault on the boundaries of the possible by trying to run a marathon in less than two hours.
Reigning Olympic marathon champion Eliud Kipchoge from Kenya, Ethiopia's Lelisa Desisa and Eritrea's Zersenay Tadese will aim to complete the classic marathon distance of 26.2 miles (42.195 kilometres) in 1hr 59min 59 sec or faster on a fixed loop at the Monza National Autodrome racing circuit in Italy.