It can be demoralising as towards the end of a race those tired legs just refuse to keep up with the gang. Here are the pros' top tips:
Javed Bhatti discovered mid-ultra fartlek sessions: “Challenge a fellow competitor to 2min at a 5k pace – your muscles and mind will soon be reinvigorated,” he suggests.
“Make sure you’ve got your pre and during nutrition nailed,” says Jayson Cavill, “and eat little and often.”
“Stick to your race plan,” is Debbie Martin-Constani’s advice, “and don’t get pulled along too fast at the start.”