The first time I ran a marathon (in Mumbai in 2013), I did it as part of a group raising funds for charity. In June 2016 I'll be taking on my first (possibly last) ultramarathon, running 69 miles along the length of Hadrian's Wall in the UK in 24 hours or less. As it's my first time facing this sort of distance, I thought I should use it to help somebody.

I asked my daughter who we should help (she has volunteered to coach me, which has so far taken the form of impersonating Shia LaBoef and screaming "YESTERDAY YOU SAID TOMORROW! SO JUST DO IT!"). 

She told me we should help everybody. Everybody who has no access to clean water. All of the 900 kids who die every day through diseases contracted through drinking to stay alive. 

My daughter is very smart.

We'd love to raise £10 for every mile of The Wall. £10 is a well dug in a village. £690 is 69 villages pulled out of water poverty, where children won't die from diarrhoea, and girls won't have to give up their education and future to walk miles every day to fetch water that it could kill them to drink.