Black, white and shades of grey - what's behind sprint's race divide?

In late 2009, the question everyone was asking was put to the man himself.

What made Usain Bolt – an era-defining champion of immense speed and consummate ease at just 23 – so fast?

Bolt cited his God-given talent, while crediting a diet that ranged from ultra-processed chicken nuggets to the Jamaican staple of yams. But he also pointed to the cruelties of man.

"I think over the years what makes Jamaica different is because of slavery really," he said of his sprinting roots. "The genes are really strong."

It is a hypothesis that existed before Bolt's comments and has persisted since; that the barbarity of the slave trade, which forcibly took men, women and children from Africa and exported them into forced labour in the Caribbean, Brazil, the United States and elsewhere, still echoes in modern-day track and field.