Many ultrarunners find that headlamps alone are insufficient to navigate dark technical trails.  Lightweight, compact versions typically don’t produce enough brightness for confident footing, and heavy-duty lighting systems are too, um … heavy, and cumbersome to wear while trying to maintain your speed across one tricky patch after another.

lightweight, comfortable fit

lightweight, comfortable fit

Petzl’s MYO series headlamps are designed to achieve the perfect balance between size, performance and durability – which makes them particularly suited to nighttime trail running.

Petzl MYO RXP Specs:

  • Bulb type: High-output LED
  • Beam type: Flood or spot
  • Brightness (high setting): 140 lumens, with boost mode of 160 lumens
  • Weight: 175g/6.2 oz
  • Dimensions: Lamp: 2” x 1.5” x 1.5” / Battery pack: 2.75” x 2” x 0.6”
  • Maximum beam distance: 77m in high setting, 97m in boost mode
  • Brightness levels: 10
  • Strobe: yes
  • Battery type: 3 AA or LR6 alkaline batteries, compatible with lithium and rechargeable batteries
  • Battery life (high setting, at 70 degrees): 50 hours
  • Water resistance: IPX-4
  • MSRP: $99.95

Petzl MYO RXP Review

The RXP is Petzl’s first headlamp to offer programmable output levels for customized brightness.  You can toggle from a wide beam for confident footing, to a focused beam for locating objects in the distance.  Its overall design is fairly lightweight and sits comfortably on your head, with an additional top strap if needed for security.  Light distribution is very even, and on the brighter settings, you’ll easily see every little bump in the trail.

Operation and programming are done via the main power button and the boost button atop the front casing.  As with some of Petzl’s compact lamps, these buttons are fairly small, and difficult to operate with gloved hands – and since you’re probably running in the dark, probably in the winter … you’ll probably be wearing gloves most of the time you’re using this lamp.  Petzl solved a similar problem with the ergonomically-improved Tikka XP2; it would be nice to see a similar adaptation to the RXP someday.

lamp casing, L to R: bost button, power button, battery indicator (hidden)

lamp casing, L to R: boost button, power button, battery indicator (hidden)

Pressing the power button scrolls you through four preset settings: three brightness levels, and a blinking SOS mode.  Default brightness settings are level 10 (140 lumens), level 6 (51), and level 4 (25), but the candle power can be configured in any way you’d like.  Programming the RXP is a little tricky at first, partly due to subtle differences between levels; unless you’re in a pitch-dark room, it’s hard to tell whether you’re in level 6 (51 lumens) or level 7 (59).  The user guide is easy to follow, and it shouldn’t take more than a few attempts to get your preferred settings dialed in.

external rear battery pack

external rear battery pack

Each brightness setting burns more battery power, with the first 8 levels regulated to shine at a steady brightness before switching to a dimmer reserve mode to get you to your next battery change or recharge.   Duration of regulated burning varies from 1 hour (level 8 brightness) to 35 hours (level 1), and seems somewhat low in the midranges:  levels 5-8 are regulated for 4,3,2, and 1 hour respectively.  For short duration running, this isn’t a problem – but if you want the RXP to light your way through the night, you have to make due with level 4 (25 lumens) or lower.   Whatever level you choose, the battery indicator tells you when the batteries are low (70% discharged) or spent (90%).


  • Brightness more than adequate to allow sure footing on technical trails
  • Lightweight and comfortable for everyday or long-duration use
  • Customized brightness levels for variety of applications.
  • Super-long battery life (>60 hrs) on low brightness settings
  • Compatible with rechargeable batteries


  • Rapid burn time for brightness settings above level 4 (25 lumens)
  • Small top buttons difficult to handle with gloves

Bottom Line: Petzl Myo RXP Headlamp

The MYO RXP is a great option if you often tackle technical terrain in the darkness, but don’t want to haul a cumbersome system with you out the door every morning.  Be sure to use rechargeable batteries, or your post-purchase costs could get out of hand.

Buy Now: Search for Petzl Headlamps at

About Author

Donald is a physical therapist, ultrarunner, barefoot aficionado, and father of three with more than 20 years of experience in endurance sports. When he's not training for ultramarathons, he enjoys hiking or slacklining with his family in Monterey County, CA.

1 Comment

  1. Great review. This fine headlamp would be more than adequate for the “casual” runner. The powering of this or any other headlamp with anything but recheargeables should really only occur where there is no alternative.

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