A US university lecturer has broken his own world record with a marathon 104-day rollercoaster ride at an amusement park in Germany, spending about 10 hours a day on the rails.

It wears you down a bit

Richard Rodriguez

Richard Rodriguez, 42, rode the Expedition GeForce ride - one of Europe's biggest rollercoasters - says he has now set 15 world records in marathon roller-coaster riding.

"I am very windburned. My face is very sore and I have a little backache, but I am good," Mr Rodriguez told Reuters news agency after finishing his ride.

His previous rollercoaster marathon record, set on a smaller ride at a Six Flags amusement park in St Louis last summer, was 100 days.

Measuring 62 metres at its highest peak, the Expedition GeForce features an 82-degree drop and a sideways twist.

Mr Rodriguez, who even invited a barber on board at one point to give him a haircut, said the ride was gruelling.

'Muscle fatigue'

"It got more difficult to ride and ride because of the muscle fatigue with all the G-force. It wears you down a bit."

Mr Rodriguez's progress was even monitored by a German air force doctor, as the effects of the constant G-forces of the coaster were not known, the amusement park said.

But the so-called rollercoaster king's ride was almost stopped short because of a toothache.

All that rattling had apparently broken a molar, and Mr Rodriguez was treated by a local dentist after a rather painful 95th day on the ride.

The dentist reportedly warned him that he risked haemorrhaging if he continued for much longer, and park officials advised him to stop if he was in pain.