Killer Kicks: the secret in your trainers

The trainer industry has tripled in the last 10 years, now accounting for almost half of global footwear sales. They are a fashion phenomenon.

Lynnie, 26, owns 80 pairs and still wants more. She travels to New York, the birthplace of the sneaker scene, and charts its rise from the footwear of basketball players, breakdancers and rappers to the defining fashion item of our age and an asset class unto itself, with its own stock exchange (StockX) and with collectors parting with up to $560,000 for a single pair.

How did it happen? And how can the planet possibly keep up? Every pair of trainers produced emits the same amount of carbon dioxide as a 10 mile drive - and the industry is pumping out over a billion pairs a year. She wants to know why she - and we - just can’t stop buying them.

Watch the full documentary on BBC iPlayer

Produced by Nomia Iqbal

Graphics by Naomi Goddard

Executive Producers Nisha Lilia Diu and Toby Sealey

Filmed by Hannah Livingston, Ben Mann and Andy Brownstone