There is no stopping Jamaica’s speed merchants at these Olympics. Veronica Campbell-Brown’s successful defence of her 200m title on Thursday means that the Caribbean island, with its 2.8m population, has produced athletes who have won four golds, two silvers and a bronze in the sprint events.

And that medal tally is likely to increase on Friday in the 4x100m relay finals. Jamaica’s men’s and wo-men’s teams sailed through in first place in Thursday’s heats, while both the star-studded US squads, as so often in recent years, dropped the baton on the final changeover of their races.