Not just for planning… use ultraPacer on race day! Your crew will thank you.

Curious how the live forecast is built from check-ins? Read How Active Runner Mode works, which includes a simulator you can step through.

Active vs Live

ultraPacer distinguishes between two states on race day:

• Active: The course is within its race-day time window. Active Mode is automatically enabled 12 hours before the event start time and remains active until:
  • Courses with a finish cutoff: Active Mode ends 4 hours after the final cutoff time at the finish. For multi-loop courses, the latest cutoff across all loops is used.
  • Courses without a finish cutoff: Active Mode ends 48 hours after the event start time with a distance-based extension.
• Live: The course is Active and has live tracking configured (e.g., timing mat integration). Live features such as automatic check-ins and Race Overview require tracking to be set up by the course owner.

No action is needed to activate or deactivate these modes — they turn on and off automatically based on the schedule windows and tracking configuration.

Active Mode

When your run is about to start, ultraPacer will automatically enter Active Mode.

Manually inputting check-ins

Any run on ultraPacer can utilize the Active Runner Mode features manually — no live tracking integration required.

What do you need to do?

In advance

1. In advance: share a link to your plan to your crew.
2. Crew should login and save the plan to their feed (“Save to feed” in the plan’s Actions menu) for easy access later.

On race day

3. Active Runner Mode is automatically enabled 12 hours before the start date of the plan.
4. Crew will go to your plan on ultraPacer
5. Crew will click the “Confirm start” button to set the beginning time of your run and enable later check-ins.
6. As you progress, crew can input arrival and/or departure times from aid stations by clicking the “Check in” button at waypoints (it reads “Edit” once that waypoint has a check-in).
7. Future arrival forecasts/paces dynamically update based your actual performance!

Automatic checkins

We are working to integrate multiple tracking sources into ultraPacer to utilize live tracking data (eg, timing mats). Currently the following timing sources are supported:

• ultralive.net
• opensplittime

Courses can be configured to automatically pull live tracking checkpoint data for all runners on course.

What do you need to do?

In advance

• Confirm with the course creator/owner in ultraPacer that live tracking is configured.
• Share a link to your plan to your crew.
• Crew should login and save the plan to their feed (“Save to feed” in the plan’s Actions menu) for easy access later.

On race day

• Active Mode is automatically enabled 12 hours before the start date of the event.
• After Active Mode is enabled, crew should view your plan in Live runner mode (select it from the Mode dropdown beside the Overview button at the top of the page).
• If not already synced, your crew will click the button to “Link Athlete” to connect a live-tracking bib to your plan/athlete profile.
• Your plan is supported by live data, making arrival forecasts dynamically update for your actual performance!

How the live forecast works

Every arrival time shown in Active Runner Mode after the runner’s last check-in is a forecast, re-computed each time a new check-in arrives. Here is what goes into it:

• Check-ins are fixed points. Each confirmed arrival splits the course into the section the runner has completed and everything still ahead. For every completed section the model works out the normalized pace the runner actually produced there: the flat, daylight pace that explains the time taken once the section’s hills, altitude, terrain, heat, darkness and the fade your plan already assumed are accounted for. A slow split up a big climb is not treated as a fade if the climb explains it.
• Recent splits count more. The remaining course is paced from a weighted average of those observed paces, with the later part of what you have run counting for more than the early miles. A runner who is slowing is projected from something close to their current pace rather than their average for the day. (Calibrated against a full Western States field, where it reduced forecast error in every stretch of the course.)
• The plan’s fatigue curve still applies. The observed pace is pushed through the rest of the course with the plan’s own factors, including its pacing strategy, so a runner right on plan at halfway is forecast to finish on plan rather than at an impossible even split.
• Aid-station time. Where a check-in has both an arrival and a departure, that observed stop replaces the plan’s estimate for the station. Stops still ahead use whatever the plan sets for that station, falling back to its typical delay where it sets nothing.
• Field position (tracked races). For races with live tracking, the remaining aid-station time is scaled by the runner’s place in the field, from about ×1 for the leaders to ×2 at the very back, because back-of-pack runners stop longer and slow more than a plan written for one runner assumes. The fatigue curve is scaled the same way when the forecast runs on the race’s tracking template, which is what the Race Overview leaderboard and bib-only tracking use. With a plan selected, Active Runner Mode keeps that plan’s own fatigue curve and scales only the aid-station time: the scaling stands in for a plan the runner doesn’t have, and a runner who has one is trusted to be following it.
• Cutoffs are not enforced. A plan bends its pacing to make every cutoff; the live forecast is a projection of what is really happening, so a forecast that misses a cutoff is shown as such and the waypoint is highlighted.

Race Overview

The Race Overview is for spectators. For races with live tracking connected, the Race Overview is enabled 12 hours before start. This view shows a top-ten leaderboard with estimated finish rank and finish times. Forecasts of the current locations of the whole field (on-course runners for the selected Field, plus your followed and selected runners) are shown on the map and elevation chart. Finished runners are kept off the map and chart — they sit parked at the finish — unless you select one (a runner who just finished lingers for a few minutes before dropping off). Select any runner — including one outside the top ten — to drill down. Add your own list of runners to track.

To access Race Overview, click the Overview button at the top of the page (beside the Mode dropdown).

Race Overview Tour

When you first access Race Overview, you’ll be presented with an introductory tour that walks you through the key features:

• Leaderboard controls (Field/Overall view, View Results, a Location menu — in Forecast view — to view the field approaching a chosen waypoint; runners already through it drop off after a few minutes, so you see who’s next to arrive. A Show Finished toggle appears when viewing the predicted finish)
• Legend showing athlete status indicators
• Controls for filtering and managing the display
• Map and elevation profile features

This tour helps you get oriented with all the live tracking features available.