Fundraising fitness fanatic Gavin Tiffin set off from the South Bank on his epic 2,000 mile cycle from London to Russia last Thursday.
Gavin, 34, was supported by 12 other riders for the first 80 mile leg of his journey from St Thomas' Hospital to Dover. Gavin will cycle the rest of the gruelling route solo, with a support vehicle following.
Before he completes The Cultural Cycle in St Petersburg on 3 September, Gavin will host special events in Berlin, Poznan and Warsaw to raise awareness about how the arts can be used to aid hospital recovery.
Gavin has worked at Guy's and St Thomas' as head of hospitality for more than four years.
He said before he set off: "It's reassuring that there will be a team of cyclists supporting me on my first leg, they can make sure I definitely leave the country!
"After so much planning and training, although I'm nervous, I'm really looking forward to the challenge and the events along the way. Everyone that is supporting me has one common goal, to show how music and arts can improve health and change people's lives."
Gavin will be the first person ever to attempt the route of more than 100 miles a day, in just three weeks.
The money he raises along the way will go to Evelina London Children's Hospital, Breathe Arts Health Research and MediCinema.
MediCinema was founded at St Thomas' and now runs six state-of-the-art cinemas in hospitals across the UK. Breathe Arts Health Research provides creative projects in different London hospitals to improve the recovery and experience of patients.
He added: "I think I'll be very emotional when I reach St Petersburg, but there's so much to achieve before then. I'm thinking of the journey stage-by-stage.
"When it gets tough I'll be thinking of my grandfather for motivation. He was a Royal Navy veteran who served in the Arctic Convoys delivering supplies to Russia during the war. I never got to meet him but hopefully I will make him proud."
You can keep up to date with Gavin's challenge, and track him along his route, by following him on Twitter or visiting www.theculturalcycle.org