Friends and colleagues began to say, ‘You’re a different person. What are you doing?”

I started running at night, because I was embarrassed to do it during the day. I teach poetry and creative writing in east London, and I didn’t want the children to see me sweating in the street. I loved rediscovering the city at night: the light, the traffic, the type of people you see – it all changes.

Source: My workout: Charlie Dark, 45, night runner – The Guardian