In Cycling the Earth you describe being stuck in a dead end job and feeling frustrated by your daily routine. How did you motivate yourself to make such drastic changes by cycling all the way round the world?

At the time it didn't seem so drastic, to be honest. I was in such a rut in life I just needed to do anything to add a bit of excitement into my days. Up until my 30th birthday I thought all I was doing was exhausting. By cycling around the world I thought I was finally living for the first time.

Were there moments on your journey when you wanted to give up? How did you find the strength to continue?

There were many times I wanted to give up. I was constantly cold, wet, hungry, tired and miserable, but every time I thought about giving up I would think about what I would have to go back to, and that was way more miserable than how I was feeling on the bike. Pain, hunger, tiredness - they all disappear quite quickly. But giving up lasts forever. 

Hell and High Water is a hair-raising story of your 135-day swim from Land’s End to John O’Groats. What inspired you to take on this challenge?

After I cycled around the world I was looking for the next big thing for me. I needed a personal goal that seemed out of reach. I think it's important we all do things in life which have an element of uncertainty. Trying to swim the length of Britain, which many thought was impossible, gave me the motivation to get up every morning. It gave me purpose.  

I like to do the three Fs: first, fastest, furthest. That makes me excited.

How do you set targets to make sure you reach your goals?

There are six things I always look at: food, water, sleep, muscle management, motivation, and conditions - like weather or terrain. As long as you can optimise your response to most of these, you should be able to succeed. If your plan for one or two isn't optimal, your risk of failure is much higher.

In August 2016 you completed a never-before-attempted triathlon, running, cycling and swimming the entire distance around Britain's coastline. Do you enjoy taking on challenges that other people see as extreme?

The best thing you can say to me is, "it's not possible," because then that makes me want to try even harder to prove that it is possible. I like to do the three Fs: first, fastest, furthest. That makes me excited. That gives me a reason to get out of bed. That makes me happy. 

You inspire many people to set new goals and achieve their full potential. Who has inspired you?

Many people inspire me, but I guess if I had to choose one it would be Tommy Godwin, who cycled 75,000 miles in one year in 1939, averaging over 200 miles per day. Even now that feat has been repeated, it will never be the same as trying to do it back then, with the equipment he had. He really is my endurance hero.