| What it is | Runner who accompanies a racer for sections |
| When | Usually later, harder stages |
| Provides | Company, motivation, safety, pacing help |
| Limits | Often can't carry gear / muling rules apply |
A pacer is a runner who accompanies an ultramarathoner over designated sections of a race — usually the later, harder stages — to provide company, motivation, safety, and help with pacing and decision-making. Pacers don’t run the whole race and typically may not carry the runner’s mandatory gear or physically aid them beyond what rules allow. They’re a common feature of 100-mile races.
Pacer vs crew
Runs with you on course (vs a crew at the aid station), often joining for the night miles of a 100-miler.
Frequently asked questions
What is a pacer in ultrarunning?
A pacer is someone who runs alongside an ultramarathon competitor over allowed portions of the course — typically the later, more grueling miles — to keep them company, boost morale, help maintain pace and good decisions, and provide a safety presence at night or when the runner is depleted. They run only their assigned sections, not the whole race.
What are the rules for pacers?
Rules vary by race, but pacers are usually only permitted after a certain distance or point, must follow the same course, and often cannot 'mule' — that is, carry the runner's mandatory gear, food, or water for them — or physically assist beyond what's allowed. Always check the specific race's pacer rules, as violations can cause disqualification.
Pacer vs crew — what's the difference?
A pacer runs with the racer on the trail for company and support; a crew supports the racer from aid stations without running with them, handling supplies and logistics. They complement each other: the crew preps and resupplies at aid stations, while the pacer keeps the runner moving and motivated between them.
Sources
- Pacing an ultra — American Trail Running Association
- Ultra support roles — The Mountaineers