Exercise can have a powerful impact on people struggling with addiction, as members of the Skid Row Running Club know all too well. Could this be one of the best natural ways to address withdrawal symptoms?

Skid Row in downtown Los Angeles has been a ghetto for the impoverished, marginalised and substance-addicted for a century. This small neighbourhood has a homeless population of about 4,500 and a fearsome reputation as the place you end up when you hit rock bottom. Perhaps surprisingly, it also has an early morning running club. As the sun rises and turns the sky pink, the group can be seen bobbing past the tents and supermarket trolleys of personal effects, offering a glimmer of hope.

The Skid Row Running Club meets three times a week at 5.45am and members include recovering addicts and local workers. Rain or shine, the club’s leader, a judge called Craig Mitchell, will be among them – a pillar of strength, empathy and community-mindedness, and the star of a rousing new documentary, Skid Row Marathon.