Fastpacking 101: Turning a Long Trail Day Into an Overnight Adventure
Fastpacking is what happens when trail running and ultralight backpacking overlap: moving fast and light enough to run the runnable sections, while still carrying what you need to be self-sufficient overnight. It opens up routes a normal long run can't reach in a day.
How it's different from a long training day
A long run ends at your car. Fastpacking means carrying a shelter, a sleep system and enough food to actually stay out, which changes what you pack even if the terrain and pace feel similar to a big training day. The goal is still to move efficiently, just with overnight self-sufficiency added on top.
What actually goes in the pack
Keep the sleep system as light as the conditions allow, a minimal shelter, a couple of clothing layers rather than a full change, and food that's easy to eat without cooking if you can manage it. Every extra item adds weight you'll be running with, not just carrying, so the ultralight backpacking mindset of cutting anything non-essential applies more here than on a normal hike.
Pace strategy for mixed terrain
Power hike the climbs, run the flats, and let the descents be a judgement call based on how technical the ground is and how tired your legs already are. Most experienced fastpackers don't try to run the whole route. Managing effort over a full day and into the next matters more than any single fast section.
Where a bigger pack earns its size
Multi-day fastpacking setups often run 20 to 40L, but for a single big day with an overnight push rather than a multi-day traverse, the LECAMO ROOT18 sits in a useful spot: 18L with front-to-back zoning and an external bungee system for a rolled layer or poles, built specifically for long-distance trail running and single-day fast-hiking rather than a full multi-day load.