Solstice

Distance Lock format: each submission must fall within the defined distance band. Runs outside the band are blocked from publishing to this race—not a disqualification, but a wasted effort. The exact band is in the race brief and Rulebook.

50 km total, accumulated from valid submissions inside the window. Scoring follows the mechanic—detail in the Rulebook.

Clock (UTC). The window runs 00:00 on 20 May through 23:59 on 20 June. Only activity published to Solstice inside that span counts.

After the window. The live phase closes on 20 June; official standings follow after verification. Provisional order can shift until Results out.

Fifty kilometres with a constraint on each individual run: not just any distance will be accepted. The distance lock means planning each outing to land inside the band—too short or too long, and the run does not count. Wasted attempts are a real cost across a month-long window.

The window opens in late May and runs into June. Streets is still live when Solstice starts; .execution runs alongside most of the window; Rembrandt and Mundial overlap the second half. The distance discipline compounds: the right length, at the right time, while other races are also asking.

• Session length — Every run needs to fit the distance band. Going over or under wastes the effort; calibrating the right distance each time is the ongoing task.

• Frequency — More sessions spread the 50 km into smaller pieces within the band; fewer means larger individual targets that must still fit. Each approach has a different error profile.

• When to push — The window is long, but the late June overlap with Rembrandt, Mundial, and the closing of Nairobi means the back half arrives loaded. Getting ahead of the distance early is worth something.

• Enter vs stay out — The distance lock filters harder than a standard multirun. A clean result here requires both the volume and the precision.

A completed 50 km on the Distance Lock closes the window on the solstice—the season’s turning point, in both the calendar and the standings. Solstice and .execution are the season’s two Ultra formats; each demands a different kind of sustained discipline.

At Results out, the race locks. Until then, provisional standings may still move.