I’m getting back in the saddle for a long-distance horse trek. A numb bum and bow-legged walk await.

It's part of an epic relay race from John O'Groats to London. My whole agency - all 450 of us - will cover 842 miles in total. Bikes, tandems, horses, canoes, pushchairs, trolleys, and even a pedibus (Google it) will be involved.

We’re doing it for Brain Tumour Research. Why? Because brain tumours are the biggest cancer killer of children. More people under 40 die from them than from any other cancer. Yet under 1% of cancer research funding is spent on brain tumour research.

So go on. Give everything you can.