Just spotted this,
Ben did some serious training for both the physical and mental. For the 'mind' bit most of all I've never seen someone so seriously determined.
The 'mental' bit was not only about the 'pain' but exhaustion due to sleep depravation. They had a guy from the University at Bath advising them on sleep strategy, he had one 30-40 minute sleep per day from day two on and later two longer 90 minutes (which got called 'Big Sleeps'!)
Some great stories from the crew who were accompanying him about him 'sleeping' on the bike, micro sleeps of a few seconds. Mad!
They took a broadcast quality camera and did lots of filming. Possible plan to do something with it.