I’ve had motorbike injuries all my life.

The motto with offroad biking is: if you don’t crash, you’re not trying. My worst injury was when I did the Dakar rally in 2006. It’s now in South America; in 2006, it was between Lisbon and Dakar. It’s probably the longest, biggest, most dangerous race in the world.

You’re doing roughly 700km offroad every day for 16 days. There are 260 bikes, 200 cars and trucks, and loads of support vehicles. I broke both my hands. Stupidly, I rode for the second half of the day, for 450km, with two broken hands.

I also have bad knees and shoulders. You can always tell a bike racer by the way he walks.

But it’s fun. I’m asked, why do you do it? But you never think an accident is going to happen to you.

The road casualty rate in some countries is a worry, of course, but it’s something you put to the back of your mind. Your reactions become faster, you learn to look out for problems. When I’m at lights in Britain, I’m looking in the side window of the car next to me, to see what people’s heads are doing. If someone is going to pop a U-turn, say, they’ll turn their head.

I run two or three times a week, for 30 to 40 minutes a time. I just finished my first half-marathon in October, the Royal Parks Foundation half-marathon for Unicef, because I’m a Unicef ambassador. There were 500 of us and we raised £350,000. I’m not the best. I did it in just under 2.5 hours. I ran for 10 minutes and walked for a minute and repeated that all the way. That’s a good way to do it for someone who’s not a long-distance runner.

I’m a great lover of food, but I try to be careful. If I wasn’t, I’d probably be 20st and living in a restaurant. With offroad biking, you’re using up energy. It’s a good way to keep fit – and beats going to the gym.

Charley Boorman will be signing his book Right To The Edge: Sydney to Tokyo By Any Means at 6pm on Thursday at Waterstone’s, Sauchiehall Street, Glasgow. Call 0141 332 9105 for information.