Every day was full of challenges, some gruelling , others just plain grubby.
So he put an incorrect date of birth on the application form and completed the gruelling 26 mile route.
As with any new venture, those first 12 months have been crucial - and gruelling .
The documentary filmed them preparing for the latter, and their gruelling training regime was something to behold.
David has been a paratrooper for a year after surviving a gruelling six-month training course.
This could take up to an hour and must be completed by the end of a gruelling nine-hour shift.
The scenery was breathtaking and it was a very enjoyable walk if a little gruelling at times.
Riders must complete four to five laps in one day, each of which can easily be a gruelling 25 miles long.
These were based mainly in Scotland, where the courses were as gruelling as the terrain.
Things did get a little gruelling at time, but by the time I had done 5K I knew that I was going to finish.