Pierre-Michaël Micaletti ran a total of 822.31 kilometres (510 miles) on a treadmill in northern Paris.
He started last Sunday and finished over the weekend.
News website lepoint.fr reported that an official from the Guinness World Records institution was on hand to confirm the distance.
Micaletti beat the last record of 753 kilometres, recorded by a British man in 2009 over seven days.
The new world record holder slept for just 12.5 hours over the six day, 144 hour endurance test.
His efforts doubled as a medical experiment, with his progress monitored by physiologists and sleep specialists.
Micaletti achieved his feat by taking 47 naps, each lasting just sixteen minutes.
“We noticed that as the week went on, the quality of sleep in these short naps became deeper and more reparative,” said one of the doctors on hand to monitor his progress.
Micaletti was accompanied in his quest by another athlete on an exercise bike. 56-year-old Philippe Dieumegard cycled 2,704 kilometres over the same period, despite a painful groin injury.