At half past six on Saturday morning, before the heat of the day settled in, the Cayman Islands staged its first parkrun. The early start was a concession to the Caribbean climate rather than any departure from the formula: a free, timed, volunteer-run 5k, open to anyone who cares to walk, jog or run it, finishing in time for breakfast. With it, one of the more remote corners of the parkrun map joined a movement that now spans more than 2,500 locations across some two dozen countries.

The launch is a small event by the standards of a series whose British flagship gatherings routinely draw four-figure fields, but it is a telling one. parkrun's growth over the past two years has come less from packing more runners into established events than from planting flags in new territory — island communities, smaller towns and countries without an organised recreational running culture. Organisers in Cayman have been explicit that the target audience is not the island's existing racers but the far larger group who find conventional running clubs intimidating or exclusive.

That positioning is deliberate and increasingly central to how parkrun describes itself. The organisation leans on the language of a social club rather than a race: events are timed but nobody finishes last ahead of the volunteer tail walker, walking is encouraged, and the metrics the charity celebrates publicly are as likely to be volunteer milestones as fast times. It is a formula that has proved remarkably portable, translating from British parks to South African townships, Japanese riversides and now a Caribbean shoreline.

The Caribbean debut also underlines how unevenly the movement has spread. The United States, for all its running population, still counts fewer than a hundred parkruns, while Britain alone hosts several hundred; growth in new territories tends to depend on a handful of determined local organisers securing permits, insurance and a core of volunteers. Cayman's launch followed exactly that pattern, and its organisers hope the visibility of a successful first event will do what it has done elsewhere: seed the second and third.

For the wider sport, the timing is apt. In a summer when the elite end of running has produced world records in Zurich and course records in Sydney, the quiet expansion of a free Saturday-morning 5k into new countries is a reminder of where most of running's growth actually happens. The million-event milestone the series is approaching will not be reached in Chamonix or on the Harbour Bridge, but on exactly the kind of modest seaside course that timed its first finishers this weekend.