How best to prepare for the London Marathon is something that millions of runners have grappled with for decades.
But sport scientists now claim to have have come up with a formula which should help getting ready for the challenge next weekend.
They recommend sleeping between five and 10 hours per night to avoid self doubt and drinking half a litre of water before running.
The formula also includes eating five grams of carbohydrate and 1.5 grams of protein per kilogram of their body mass every day in the week before running.
And the tips don't end there. The advice - released by Macmillan Cancer Support - also suggests avoiding crowded areas and washing your hands regularly to avoid illness.
- The 'ultimate formula' for marathon success
5C(kg/bm) + 1.5P(kg/bm) + H2O + (5-10hr)S - I - SD = Marathon success
The formula was designed by Anna Campbell, professor in clinical exercise science at Edinburgh Napier University.
Prof Campbell is an exercise adviser to Macmillan Cancer Support, which has 800 runners supporting it at this year's marathon.
The charity estimates that its runners will raise a total of £1.45 million.
Prof Campbell said: "The week before the London Marathon is a crucial time for all runners, not just to reach their fundraising targets, but to complete those final preparations for the 26.2-mile challenge ahead of them."
More than 40,000 people took part in the event last year, running the 26.2 miles (42km) from Blackheath to Westminster.