Think in Systems
A headlamp is only one part of night strategy. You need light on the course, power through the night, and enough comfort that the lamp does not become another problem at 3 AM.
Product examples live in our headlamp guide. This page is about the race plan.
Battery Math
| Race Format | Estimate | Planning Check |
|---|---|---|
| 24-hour | Darkness from the event date, location, and start time | Tested runtime at the required output, plus rule-compliant redundancy |
| 48-hour | Each dark period and the time available to recharge | Verify charging access, cable compatibility, and a failure-safe option |
| Backyard | Unknown duration and repeated departures from the aid area | Use the event rules and a repeatable check before every dark loop |
| 6-day | Multiple dark periods, charging windows, and changing weather | Track charge state and keep required backup equipment functional |
Testing
Test the lamp on the settings and terrain you expect to use, not only the brightest setting on the product page. Manufacturer runtime can be measured under conditions that differ from your weather and use.
- Test long enough to observe output changes and pressure or bounce.
- Wear the same hat, buff, or glasses you expect to use.
- Check bounce, forehead pressure, and whether buttons work with gloves.
- Rehearse charging or battery swaps in a safe, well-lit place.
- Compare settings without reducing light below what safe footing requires.
Backup Plan
If a light fails, stop at a safe place before troubleshooting or changing batteries. Do not continue over technical or unlit ground with inadequate visibility. Any required backup must stay with you as the rules specify; otherwise, decide where to carry it from the distance to the next staffed aid point or safe exit, not merely the distance to crew.
Add lights, cables, and batteries to the gear checklist generator before race week.
Sources
- Petzl — official explanation of brightness, beam shape, and burn-time tradeoffs.
- Petzl — ANSI/PLATO FL 1 lighting-performance measurements.
- Eiger Ultra Trail by UTMB — official mandatory-equipment example; check your own event's current rules.
Frequently Asked Questions
How many headlamps do you need for a 24-hour race?
Carry every light and power source required by the current race rules. Where the rules do not specify a number, choose redundancy from the hours of darkness, terrain, remoteness, aid access, weather, and the consequence of a failure; test the complete system before race day.
How many lumens do you need for an ultra?
There is no universal lumen target. Required visibility depends on speed, terrain, markings, weather, other runners, and individual vision. Follow any event minimum and test beam shape and usable output on comparable ground rather than relying on peak lumens.
Should you use reactive lighting?
Reactive lighting can save battery and reduce fiddling, but test it first. Some runners prefer predictable manual settings in fog, rain, groups, or reflective environments.